1977 400 engine VIN location and 383 differences

Metalmarty

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Hi All,

I've got some questions about a 1977 400CID engine.
I am pretty familiar with the 383B and 440RB engine, but the 400B is fairly new to me.

Where can I find the engine number/VIN on a 1977 400 engine from a Chrysler Newport? I tried looking on the flat surface just above the oil pan on the passenger side. It has the flat surface but it didn't look like it ever had any numbers on it. Are there other places to look?

What are the differences between a 1977 400 engine and a 1968 383 engine?
- I know that the 400 pistons are different (bigger bore) but everything else in the engine is the same as 383? (cast crank instead of steel but same otherwise)
- If I understood correctly the harmonic damper and torque converter are different. Externally balanced on the 400 because of a cast crank, internally balanced steel crank on the 383.
- The motormount ears on the 400 are a little thicker than the 383 so the ears won't break off.

The reason asking.
As some of you know, I need a lot of money to get my 383 up and running again which is not in budget for the forseeable future. I looked at temporary options but they are slim in my area.

Until last weekend. I found a 400CID engine in decent shape. It's all complete in one piece with carb, ignition, fan, air cleaner, manifolds, torque converter, TF727 transmission etc. The price was good enough to take a look.

For my understanding the 1968 383 and 1977 400 are the same externally.
Would I be able to drop in the 400 without any issues instead of the 383? (keeping the TQ in mind because of the balancing)

Ofcourse with some cleaning, new plugs, oil etc :)
I already have a new ignition system and a edelbrock dual plane intake with an edelbrock 1406 600CFM carb which I can use to replace the lean burn system. :p
 

68 4spd Fury

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I can't answer all your questions, I'm not that familiar with them either. My experiences is with the 383 also. There is a pad below the distributor that has Engine numbers on it, displacement and and over/under size codes. The VIN ID was located on the back of the block by the oil pressure sender. There is no difference in size between the two so fit won't be an issue. The cast vs. steel crank and any other internal differences I can't speak to but I'd assume there are many. Good luck.
 
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cbarge

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In short, the 400 will fit in your Newpie.
Just use the 68 motor mounts, exhaust manifolds.
I recommend the B&M flexplate for externally balanced ebgines so you can still use the 68 torque convertor without weldibg on weights or replacing the convertor for no real reason.
I had used the B&M flexplate on externally balanced motors with no issues.
That helps greatly when you want to use any 727 convertor of your choice with no modifications.
383/400 intakes are the same regarding size. Bolt her on.
 

70bigblockdodge

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Drop it in. Deck heights are the same so exhaust and brackets will bolt up.
Use the B&M flexplate as listed and you can keep you stock 68 converter.
 

Metalmarty

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I can't answer all your questions, I'm not that familiar with them either. My experiences is with the 383 also. There is a pad below the distributor that has Engine numbers on it, displacement and and over/under size codes. The VIN ID was located on the back of the block by the oil pressure sender. There is no difference in size between the two so fit won't be an issue. The cast vs. steel crank and any other internal differences I can't speak to but I'd assume there are many. Good luck.

Thanks for the information, much appreciated.
I know the location of the displacement etc under the distributor.
I haven't found a VIN close to the oil pressure sender and above the oil pan yet.
I didn't have too much time to look at it yet though...

In short, the 400 will fit in your Newpie.
Just use the 68 motor mounts, exhaust manifolds.
I recommend the B&M flexplate for externally balanced ebgines so you can still use the 68 torque convertor without weldibg on weights or replacing the convertor for no real reason.
I had used the B&M flexplate on externally balanced motors with no issues.
That helps greatly when you want to use any 727 convertor of your choice with no modifications.
383/400 intakes are the same regarding size. Bolt her on.

Thanks Cbarge. Great information as always.
I just found the B&M flexplate before I saw your post, good to hear that it works fine.
I had a refurbushed factory 10-3/4" high stall converter on the way before I knew that my 383 was in such bad condition.
So I was looking if I could use it by adding weights to it, but the B&M flexplate might be the better option.

Drop it in. Deck heights are the same so exhaust and brackets will bolt up.
Use the B&M flexplate as listed and you can keep you stock 68 converter.

Thanks for the info!
Great to hear that it is all this simple so far.

I'm picking up the engine this friday if everything works out.
Anyone knows where I can find engine ID numbers on a 1977 400 engine (apart from the distributor pad)?
 

77newyorker440

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I don't know much about the external engine differences, but I am looking forward to hearing your experience with changing out the lean burn on that 400 because I am planning on doing the same thing on my 77 440.
Good luck,
77newyorker440
 

70bigblockdodge

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I don't know much about the external engine differences, but I am looking forward to hearing your experience with changing out the lean burn on that 400 because I am planning on doing the same thing on my 77 440.
Good luck,
77newyorker440
Once the carburetor (Thermoquad) and the no advance distributor and it's associated air cleaner box are gone, so is the lean burn. The carburetor runs lean at idle and cruise, WOT is unaffected. Ignition is slow and retarded to reduce emissions, with multi-strike spark to help drivability.
If he uses his 1968 distributor and carburetor the lean burn is gone. I would use the '77 intake, plenum volume is greater.
Partial VIN is on the passenger side pan rail toward front only the last 6 numbers.
 

77newyorker440

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Once the carburetor (Thermoquad) and the no advance distributor and it's associated air cleaner box are gone, so is the lean burn. The carburetor runs lean at idle and cruise, WOT is unaffected. Ignition is slow and retarded to reduce emissions, with multi-strike spark to help drivability.
If he uses his 1968 distributor and carburetor the lean burn is gone. I would use the '77 intake, plenum volume is greater.
Partial VIN is on the passenger side pan rail toward front only the last 6 numbers.
Do the wires connect to the lean burn box have to be disconnected from anything else other than the ignition?
Thanks for all of the info,
77newyorker440
 

Metalmarty

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I don't know much about the external engine differences, but I am looking forward to hearing your experience with changing out the lean burn on that 400 because I am planning on doing the same thing on my 77 440.
Good luck,
77newyorker440

I will post my findings when I have them, can take a while though :)

Once the carburetor (Thermoquad) and the no advance distributor and it's associated air cleaner box are gone, so is the lean burn. The carburetor runs lean at idle and cruise, WOT is unaffected. Ignition is slow and retarded to reduce emissions, with multi-strike spark to help drivability.
If he uses his 1968 distributor and carburetor the lean burn is gone. I would use the '77 intake, plenum volume is greater.
Partial VIN is on the passenger side pan rail toward front only the last 6 numbers.

I will check again on the passenger side for the VIN.
Couldn't find anything on that pad last monday. I cleaned it and gave it a light sanding but I couldn't find anything remotely resembling numbers.
I'll be picking the block up on friday, will check again then.
 

70bigblockdodge

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Do the wires connect to the lean burn box have to be disconnected from anything else other than the ignition?
Thanks for all of the info,
77newyorker440
Not really if you want to leave it for originality look.
If you put in a regular Chrysler electronic ignition you will change the distributor so the old leads can just be abandon. You will need to parallel the coil and distributor harness on passenger side valve cover, and you need the bottom half of the ballast resistor, and a keyed ignition source.
 

Metalmarty

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I took home the 1977 400 today!
The engine is from a 1977 Chrysler Newport.

What is the normal cranking compression on a bone stock 1977 lean burn 400 engine? I did a compression test and I got numbers ranging from 135-150psi on all 8 holes. Lot higher than I expected from a "advertised" 8.2:1 compression engine (probably around 7.5:1 real numbers) .

IMG_20201023_143429.jpg


IMG_20201023_143440.jpg


IMG-20201023-WA0007.jpg


A 1977 Chrysler Newport normally has a 11.75" torque converter right? Looks like it has a 10.75" converter in it now? Is this a chrysler HP (higher stall) converter?
IMG_20201023_161736.jpg
 

70bigblockdodge

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That's pretty good cranking compression from a '77. I'd run with that.
The converter is nothing special, everything was low stall in the emission, fuel crisis era. I believe they went to those smaller converters across the board BB, small blocks, trucks, cars. I think to reduce inertia because power was down and one size part fits all. The fins inside are probably angled different for different applications. The 73 up passenger side water pump housing was also a standardizing part to use same radiator as small block.
 

Metalmarty

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Thanks for the info.

The engine looks really good.
I'm thinking of swapping the cam before dropping the engine in.

How much lift would be the max for 452 heads?
I'm thinking of the howards rattler cam 728001-09 with .480/.488 lift, 227/235@.050

Not sure if this is too big with my compression ratio.
Will this cam be a problem with my power brakes?

What are other suggestions?

Other upgrades will be:
- Edelbrock DP4B intake and Edelbrock 1406 (600cfm) carb
- Rick Ehrenberg electronic ignition system
- Headman 78070 headers
- Chrysler 10 3/4" HP stall convertor (~2300rpm stall)
 
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