Cam swap worth it? '68 383 newport

Metalmarty

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Hi all,

More questions!
I've got a '68 Newport.
It still has the original 383 with 9.2:1 compression in it with a TF727 behind it.
The intake was swapped by the previous owner with a Edelbrock DP4B aluminium intake.
The current carburetor is a Edelbrock 1406 600CFM 4 barrel carb.
Points ignition was swapped with Mopar electronic ignition.

Engine is stock apart from those changes (Stock block, pistons, heads etc).
It has the stock log manifolds going to a single pipe going to the back.
I'm taking the 383 out of the car in the upcoming months to refresh bearings, rings, seals, gaskets etc.

It is worth it to spend an extra 200usd or so for another camshaft?
Or won't that make a big difference with stock heads, stock exhaust and 600CFM carb.
(I might swap to dual exhaust sometime later on)

If so, what camshaft do I want? (out of the 100s available)
I like an engine with a lot of torque and I like some rough idling (not too much)

I've also read some articles about special Mopar camshafts that make use of the big lifters (steeper cam lobes). It is worth buying this?
 
It would only make sense to replace the cam at that point. I’d go a little lumpier as far as cam specs but wouldn’t stray too far from what Ma Mopar was using back in the day. I’m not going to stand behind any particular brand but I will say I won’t buy anything from Comp Cams anymore.
 
Thanks for the info @detmatt
I will look around for the camspecs that Ma Mopar used.
Do you know some cam specs that puts me in the ballpark to make the search a bit easier? If not, no problem.

Are you able to elaborate why you won't buy anything from Comp Cams anymore? I'm curious since they seem to have a big assorment of cams for mopars.
 
You can go with an RV cam grind that will work with the stock valve springs, stock compression, and single exhaust with duals down the road. Oh and the highway gears too.
Any lumpier you will have to change the valvetrain to match the cam.
Summit has a good choice of Mopar cams worth looking into.
Mopar used to have a 260/260 grind that can haul the mail and be civil in town.
Hope this helps
 
Hi all,

More questions!
I've got a '68 Newport.
It still has the original 383 with 9.2:1 compression in it with a TF727 behind it.
The intake was swapped by the previous owner with a Edelbrock DP4B aluminium intake.
The current carburetor is a Edelbrock 1406 600CFM 4 barrel carb.
Points ignition was swapped with Mopar electronic ignition.

Engine is stock apart from those changes (Stock block, pistons, heads etc).
It has the stock log manifolds going to a single pipe going to the back.
I'm taking the 383 out of the car in the upcoming months to refresh bearings, rings, seals, gaskets etc.

It is worth it to spend an extra 200usd or so for another camshaft?
Or won't that make a big difference with stock heads, stock exhaust and 600CFM carb.
(I might swap to dual exhaust sometime later on)

If so, what camshaft do I want? (out of the 100s available)
I like an engine with a lot of torque and I like some rough idling (not too much)

I've also read some articles about special Mopar camshafts that make use of the big lifters (steeper cam lobes). It is worth buying this?

Since you are going so far as to completely tear down the engine, it definitely makes sense to replace the cam. I would go with a complete cam kit (cam, lifters, push rods, springs, etc.). Take a look at "dual pattern" cams where the exhaust has a little more duration and lift than the intake. You want a cam that pulls good from about 1500 to 5000 rpm. In addition to the foregoing, I would install a good dual exhaust system on the car and have a competent shop do a valve job on the heads. Yer heads are pretty good ones with 2.08 intake and 1.74 exhaust valves, and your compression is at about 9.2 : 1.

Despite what Matt says, I used a complete Comp Cams kit when I had my 440 rebuilt, and I'm very happy with it's performance and throttle response. Here is the cam I used: Xtreme Energy 218/224 Hydraulic Flat Cam for Chrysler 383-440 If you don't like Comp Cams, you can use the specs on this one as a guide.
 
Let’s just say if I were living by the once bitten twice shy guideline I should’ve blacklisted them two bite wounds ago. The last time was lifters that began to fail after maybe 500 miles on a fresh engine. After some discussions with my engine builder about increasing quality control issues with them over the years I’m just going to avoid them.
 
Let’s just say if I were living by the once bitten twice shy guideline I should’ve blacklisted them two bite wounds ago. The last time was lifters that began to fail after maybe 500 miles on a fresh engine. After some discussions with my engine builder about increasing quality control issues with them over the years I’m just going to avoid them.

I hear ya. . . I hope I don't end up going down that same road. I went with my engine builder's recommendation regarding the selection of a Comp Cams cam. He has built many race engines over the years, and has installed a lot of Comp Cams cams.
 
Here's what you've got, what I call the 2 barrel cam, very mild:

The 1968 ~ 383/330 HP and 383/300 HP 'Super Commando' Camshaft

Lift............. 431"/.443"
Duration.... 256*/260* Duration
Overlap..... 32* Overlap

Valve Springs........ #134 lbs. Valve-Closed / #208 lbs. Valve-Open

Next is the "magnum" / roadrunner cam:

The 1968 383/335 HP 'Road Runner' and 440/375 'Super Commando'
utilized the same Camshaft.

Lift............. 450"/.458"
Duration..... 268*/284*
Overlap....... 46*

Valve Spring Load-Rate....... #129 lbs. Valve-Closed / #250 lbs. Valve-Open

This is a Crane, used to be known as HMV 278, I wouldn't go above this for your application:

Crane PowerMax Cam and Lifter Kits 683802
278/290, Lift .467/.494,

Advertised Intake Duration: 278
Advertised Exhaust Duration: 290

It's a nice cam in a 455 or a 505, might be a touch rough in a 383?
 
Next is the "magnum" / roadrunner cam:

The 1968 383/335 HP 'Road Runner' and 440/375 'Super Commando'
utilized the same Camshaft.

Lift............. 450"/.458"
Duration..... 268*/284*
Overlap....... 46*

This is the one I would think about going with. Maybe advance it a degree or two, maybe not.

That said, the best bet is to call the cam company for a recommendation. Not Jegs or Summit... Call the cam company of choice. They all have people on staff that will plug in your specs and come up with a cam. I think I would call Hughes... They seem to have Mopar specific grinds rather than the Chevy profile that you might get at most other places.
 
You can go with an RV cam grind that will work with the stock valve springs, stock compression, and single exhaust with duals down the road. Oh and the highway gears too.
Any lumpier you will have to change the valvetrain to match the cam.
Summit has a good choice of Mopar cams worth looking into.
Mopar used to have a 260/260 grind that can haul the mail and be civil in town.
Hope this helps

Thanks for the info cbarge! I don't mind swapping springs if needed and if they are not too expensive. They'll come off anyway to replace valve stem seals.
Will look into it.
How do you like the cam you have in your barge? Just perfect, too mild, to rough?

Since you are going so far as to completely tear down the engine, it definitely makes sense to replace the cam. I would go with a complete cam kit (cam, lifters, push rods, springs, etc.). Take a look at "dual pattern" cams where the exhaust has a little more duration and lift than the intake. You want a cam that pulls good from about 1500 to 5000 rpm. In addition to the foregoing, I would install a good dual exhaust system on the car and have a competent shop do a valve job on the heads. Yer heads are pretty good ones with 2.08 intake and 1.74 exhaust valves, and your compression is at about 9.2 : 1.

Despite what Matt says, I used a complete Comp Cams kit when I had my 440 rebuilt, and I'm very happy with it's performance and throttle response. Here is the cam I used: Xtreme Energy 218/224 Hydraulic Flat Cam for Chrysler 383-440 If you don't like Comp Cams, you can use the specs on this one as a guide.

Thanks for the info and link.
Same question as to cbarge: "How do you like the 218/224 (262/270) cam? Just perfect, too mild, to rough?

Let’s just say if I were living by the once bitten twice shy guideline I should’ve blacklisted them two bite wounds ago. The last time was lifters that began to fail after maybe 500 miles on a fresh engine. After some discussions with my engine builder about increasing quality control issues with them over the years I’m just going to avoid them.

Thanks for the info matt!

Lunati makes a good cam. I have a MoPar "purple shaft" spec cam in my '66 383 and am very happy with it.

Thanks for the info, will look into it!
Which lunati cam PN do you have? (10211005?)

Here's what you've got, what I call the 2 barrel cam, very mild:

The 1968 ~ 383/330 HP and 383/300 HP 'Super Commando' Camshaft

Lift............. 431"/.443"
Duration.... 256*/260* Duration
Overlap..... 32* Overlap

Valve Springs........ #134 lbs. Valve-Closed / #208 lbs. Valve-Open

Next is the "magnum" / roadrunner cam:

The 1968 383/335 HP 'Road Runner' and 440/375 'Super Commando'
utilized the same Camshaft.

Lift............. 450"/.458"
Duration..... 268*/284*
Overlap....... 46*

Valve Spring Load-Rate....... #129 lbs. Valve-Closed / #250 lbs. Valve-Open

This is a Crane, used to be known as HMV 278, I wouldn't go above this for your application:

Crane PowerMax Cam and Lifter Kits 683802
278/290, Lift .467/.494,

Advertised Intake Duration: 278
Advertised Exhaust Duration: 290

It's a nice cam in a 455 or a 505, might be a touch rough in a 383?

Thanks for the list!
Seems that duration @.050 needs to be somewhere between 216-222 on the intake and 224-234 on the exhaust?

How big should the lobe seperation be?
And what is the max lift I can get away with, with stock heads/pistons?


I prefer to just buy a cheap cam that suits the current engine configuration and has some room for dual exhaust for example.
I can swap valve springs and lifters if it doesn't get too expencive, but if it isn't needed, great.

I have to rebuild the whole front end, the engine refresh is happening because it'll be out anyway. A cam upgrade is a nice to have, but I don't want to spend big money to upgrade the whole valvetrain to suit a new cam. So I'm looking for a nice in between.

Rough idle is fine, and rpm range from 1500 till 5000-5500 is best I guess?

This is the one I would think about going with. Maybe advance it a degree or two, maybe not.

That said, the best bet is to call the cam company for a recommendation. Not Jegs or Summit... Call the cam company of choice. They all have people on staff that will plug in your specs and come up with a cam. I think I would call Hughes... They seem to have Mopar specific grinds rather than the Chevy profile that you might get at most other places.

Thanks John.
That's also a question I still have. A lot of cams seem to have a generic grind instead of the Mopar big lifter grind.
What do I look for to see if a cam has a Mopar grind.
I've notice that Hughes does have it like you've said, but in other companies?
 
How do you like the cam you have in your barge? Just perfect, too mild, to rough?
Comp Cams 268H .474 lift beehive springs,stock pushrods and rockers.
Nice idle where you know there is a cam in it but smooth. excellent throttle repsonse in all RPM ranges.
Keep in mind the cam is just a part of the "package"
When you change one thing,it affects another.
Do your homework to make sure everything works TOGETHER.
Wehn I opted to go with my cam,I upgraded my torque convertor,upgraded the trans,and exhaust.
Also swapped out the rear gears and made sure I had 28 inch tall tires.
For a better understanding,next time you are over this way drive my car.
 
Last edited:
As Steve Dulcich once told me about cams! Keep your duration NO more than 10% over the stock duration, and your lift NO more than .050" over the stock lift, you will have one sweet running street motor! Good Luck
 
Comp Cams 268H 4.74 lift beehive springs,stock pushrods and rockers.
Nice idle where you know there is a cam in it but smooth. excellent throttle repsonse in all RPM ranges.

DECADES ago, I called comp cams for a recommendation for an upgrade to the "roadrunner" cam, their response was "that's a tough cam to beat" and suggested the 268H. FWIW.

Overlap, more is better for idle quality, 114 is fairly typical for street cars, 106 to 108 for nervous idlers. With your 9.2 compression you should have adequate valve to piston clearance with the Crane cam I mentioned. But you HAVE to check it yourself.

With stock rear gears, stock "tight" converter the Crane might be too much, low end might be soggy, idle vacuum might be a bit low. I'm not sure, never tried it in less than a 455. John is correct, it's a generic grind, you can call it a chevy grind if you like, but it's a good dual pattern camshaft.

On the other hand you already have a working and known combination, it's good for 330 hp in a 4 bbl dual exhaust configuration. Figure about 4% power difference per compression ratio from ~ 8 - 12-1. You're down .8 in compression ratio from the HP 383 engine though, about 11 HP, so roughly 319 hp. The upside is less octane requirement. According to the factory the roadrunner cam is only 5 additional HP, I don't buy that but that's their rating.

I hope my rambling is of some help.
 
That's also a question I still have. A lot of cams seem to have a generic grind instead of the Mopar big lifter grind.
What do I look for to see if a cam has a Mopar grind.
I've notice that Hughes does have it like you've said, but in other companies?

That's a good question and one that I really don't know the answer to. I haven't shopped for a cam for years now and a lot of things have changed. Hughes does seem to be a cam of choice for a lot of Mopar guys.
 
That's a good question and one that I really don't know the answer to. I haven't shopped for a cam for years now and a lot of things have changed. Hughes does seem to be a cam of choice for a lot of Mopar guys.

Hughes Engines specializes in Mopar parts, so I am inclined to agree with Big John. I just bought their rockers arms and they are awesome looking.
 
Comp Cams 268H .474 lift beehive springs,stock pushrods and rockers.
Nice idle where you know there is a cam in it but smooth. excellent throttle repsonse in all RPM ranges.
Keep in mind the cam is just a part of the "package"
When you change one thing,it affects another.
Do your homework to make sure everything works TOGETHER.
Wehn I opted to go with my cam,I upgraded my torque convertor,upgraded the trans,and exhaust.
Also swapped out the rear gears and made sure I had 28 inch tall tires.
For a better understanding,next time you are over this way drive my car.

Which torque converter did you get with your combo, and you have 3.23 gears right?
Swapping the 2.76's to 3.23's and dual exhaust is on the list of first upgrades after the car is driveable.

I know that a cam ties everything together. I've build my own engine for my VW beetle. A 1.9L big bore engine with a great torque curve and good horsepower. All the machine work including milling the shortblock to fit the bigger pistons and cylinders (single barrels) was done in house by myself. I can find my way around with old VW aircooled engines, but big american v8's is new for me.

This is also the reason why I'm asking, I want a cam that fits my combo just right. And I was curious to hear some info and opinions on this forum :) All to get new info, learn and make better decisions.

As Steve Dulcich once told me about cams! Keep your duration NO more than 10% over the stock duration, and your lift NO more than .050" over the stock lift, you will have one sweet running street motor! Good Luck

+1 for Steve Dulcich. I like that man very much. Thanks for the info.

DECADES ago, I called comp cams for a recommendation for an upgrade to the "roadrunner" cam, their response was "that's a tough cam to beat" and suggested the 268H. FWIW.

Overlap, more is better for idle quality, 114 is fairly typical for street cars, 106 to 108 for nervous idlers. With your 9.2 compression you should have adequate valve to piston clearance with the Crane cam I mentioned. But you HAVE to check it yourself.

With stock rear gears, stock "tight" converter the Crane might be too much, low end might be soggy, idle vacuum might be a bit low. I'm not sure, never tried it in less than a 455. John is correct, it's a generic grind, you can call it a chevy grind if you like, but it's a good dual pattern camshaft.

On the other hand you already have a working and known combination, it's good for 330 hp in a 4 bbl dual exhaust configuration. Figure about 4% power difference per compression ratio from ~ 8 - 12-1. You're down .8 in compression ratio from the HP 383 engine though, about 11 HP, so roughly 319 hp. The upside is less octane requirement. According to the factory the roadrunner cam is only 5 additional HP, I don't buy that but that's their rating.

I hope my rambling is of some help.

Please, keep on rambling. If it's useful information I'll have it all :)

The 268H seems a bit on the smaller size? For engines from 8:1 to 9:1 compression and "only" 218 @.050 on intake and exhaust. Nevertheless, thanks for the info. It's worth comparing everthing. This makes it easier for me to find something that will be in the ballpark.

How big can you go with a cam before you run into issues with the stock converter with a heavy '68 newport? It currenly has 2.76 gears but I'm considering a swap to 3.23's.

That's a good question and one that I really don't know the answer to. I haven't shopped for a cam for years now and a lot of things have changed. Hughes does seem to be a cam of choice for a lot of Mopar guys.

Thanks for the message again. Hughes looks good. I will send them a message to get some info for my specific combo.

Hughes Engines specializes in Mopar parts, so I am inclined to agree with Big John. I just bought their rockers arms and they are awesome looking.

Thanks for the input also :)

I'm runnin a old Hughes grind, 2330 cam. I like it!

Another one for Hughes. Great!


So I was just thinking of a cam swap for now with future upgrades like dual exhaust and swapping 2.76's in the rear end for 3.23. Do I also need to consider a different converter with these changes? I have no idea what the specs of the stock converter are and how to pick one. Everything I had so far is stick shift.
 
Which torque converter did you get with your combo, and you have 3.23 gears right?
Swapping the 2.76's to 3.23's and dual exhaust is on the list of first upgrades after the car is driveable.



I know that a cam ties everything together. I've build my own engine for my VW beetle. A 1.9L big bore engine with a great torque curve and good horsepower. All the machine work including milling the shortblock to fit the bigger pistons and cylinders (single barrels) was done in house by myself. I can find my way around with old VW aircooled engines, but big american v8's is new for me.

This is also the reason why I'm asking, I want a cam that fits my combo just right. And I was curious to hear some info and opinions on this forum :) All to get new info, learn and make better decisions.



+1 for Steve Dulcich. I like that man very much. Thanks for the info.



Please, keep on rambling. If it's useful information I'll have it all :)

The 268H seems a bit on the smaller size? For engines from 8:1 to 9:1 compression and "only" 218 @.050 on intake and exhaust. Nevertheless, thanks for the info. It's worth comparing everthing. This makes it easier for me to find something that will be in the ballpark.

How big can you go with a cam before you run into issues with the stock converter with a heavy '68 newport? It currenly has 2.76 gears but I'm considering a swap to 3.23's.



Thanks for the message again. Hughes looks good. I will send them a message to get some info for my specific combo.



Thanks for the input also :)



Another one for Hughes. Great!


So I was just thinking of a cam swap for now with future upgrades like dual exhaust and swapping 2.76's in the rear end for 3.23. Do I also need to consider a different converter with these changes? I have no idea what the specs of the stock converter are and how to pick one. Everything I had so far is stick shift.

Going by what you're saying you want, yes, I would upgrade the TC. Something in the 2400-2800 stall would keep it streetable with the 3.23 rear. At that point you could consider a slight upgrade mod to your tranny, such as a Transgo kit. You don't need to go crazy with it, you aren't street racing quarter miles, but you'll notice a difference with what you're modifying.

Back to the TC, I would suggest rebuilding yours rather than buying a TCI, B&M, etc. You may have to look in your area for a tranny guy to give you a TC rebuilder suggestion or maybe some of the guys on this site will recommend one. Just my 2 cents.
 
So I was just thinking of a cam swap for now with future upgrades like dual exhaust and swapping 2.76's in the rear end for 3.23. Do I also need to consider a different converter with these changes? I have no idea what the specs of the stock converter are and how to pick one. Everything I had so far is stick shift.

I forgot to add, thanks for the reminder. With what Dulcich said also was with that change, you can still use/keep the stock converter. Good Luck
 
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