Junkyard 360 performance build questions

[Bart]

Hi all,
I am putting together the 360 in my 71 Fury III soon. I have to build it on a budget so I can get her on the road. I will be running stock compression in the original engine. I would like a couple of informed opinions. I have 2 manifolds; an older Edelbrock Performer 318/360, and a Weiand Stealth. I also have 2 cams laying around, a Summit 258 or 260 single pattern with a lift in the neighborhood of .440 that I ran in a truck, and a Comp cams 268/276 with .464 lift. It is a 268AH-10, their version of the 340 cam. What combo do think will move the Fury better? I have a 3.31 open rear end 8.75, which will be closer to 3.23 because it came out of a 62 Dart with 14" tires. 727 will be rebuilt with a shift kit. Ready, GO!

 

[C Body Bob]

Neither of those's intakes are going to make any power. There are basically aluminum versions of the stock intake. Prefer the Eddy. These are good intakes if you are doing a 2 to 4 barrel swap & want a stock smooth ideling & power band. Make sure they have the A/C bosses. I'd use the comp cam. That 3.31 gear may be a 741 case. Weaker than the later versions. Sell the intakes & get an old Eddy CH4B or a newer Performer RPM & find a 3.55 gear sure grip. 600 carb. Heat spacer if you are in a warm climate. You will pick up half second on a 1/4 mile & still be a very driveable street car

 

[Bart]

The Stealth intake is the equivalent of the RPM. I was leaning towards the 268 cam, but worried with the higher lift and quicker ramp speed than the "factory" 340 cam, it would be a dog on the street. I will be putting new gaskets, bearings, and rings in it, but I will be lucky to have 8.5:1cr. I should also mention the heads I have are mildly ported and polished.

I know they put the 340 cam in the HP 360 with low compression, but I am not sure if this cam will Show similar performance. I was hoping someone could answer that question.

The case is a 741. It should be plenty for what I am doing now. It will eventually find its way into my wife's 66 Fury (290 +/- hp 318 poly).

 

[C Body Bob]

I have never run a Weiand intake. I always thought it was called "Stealth" because it was a copy of the factory intake. Anyway if it's not taller or have bigger runners & ports than a stock 4 bbl then it ain't gonna make no power. I think Eddy advertises their low rise performer makes s tiny bit more RPM. As for the cam. That's real close to the cam I have in my 8:1 318. And it runs great to 5500. Has a 1.89 60 ft. That ain't much cam. You can always degree it. I installed mine straight up. I run 87 pump.

 

[Bart]

Thanks, Bob. I just don't want to put it together and regret it for the next 2-3 years until I have the money for a complete overhaul. I have more experience with B and RB motors, and B body cars. I finally dialed in the 360 in my truck, but I went through 3 cams doing it. I am trying to avoid that situation again!

I contacted the Comp Cams guy before I posted here, and he said I should really have 9:1 for the 268AH-10, but I also knew the similar cam was the HP cam for the 360 smog motors back in the day... That is why I posted the question on this board. Someone has to have this cam in a nearly stock C body, right?

By the way, The Stealth is a high rise with large ports. The Action + Plus is the factory replacement. I have one of those, too. It has larger ports than the Performer.

 

[C Body Bob]

Check those ports on the intake with a gasket. Just to make sure they line up good.

 

[Bart]

Yup. The ports are just slightly smaller than the heads. I am not going to mess with them right now, because I plan on rebuilding the J heads from the '71 at a later date and matching them to the intake. This is an intermediate engine. I just don't want a dog off the line

 

[C Body Bob]

You"ll be fine. I was looking through my Comp catalog. They pretty much recomend 9:1 on every mild street cam they sell. Back in the 80's I ran an auto parts store. Sold a lot of cams to the 305 IROC Z crowd. Way bigger that yours. These cars where lighter, but a 305. The 80's LoL

 

[moper]

The Comp cam and the 318/360 performer intake. I use that intake on my truck's 360. It's all torque which is what you want in that car with those gears.

 

[70bigblockdodge]

Eddy manifold and the lame comp cam only because its paid for and better than the other free cam.

 

[Bart]

Why the Eddy vs Weiand? Also, even though this is not on the table due to budget constraints for now, what cam are your thinking? Any real world comparison?

 

[70bigblockdodge]

A Eddy performer is a proven manifold over and over. A stock 340 or 383/440 magnum cam is the lowest starting point for any type of rebuild, replacement unless you really want a 318 2bbl cam why they are same price. Everybody whit a pluse wants a rumpity rump idle and none of the cars are being driven by secrataries that know where the gas and windshield washer fluid go only. I am just not a fan of Comp Cams they make good products but I think their low end street hp cams are kind of generic i.e. chevy lobes on whoevers blank.

 

[Bart]

So, ultimately, what is your ideal build for a small block, 4,000 cruiser with mid-range gears?

 

[70bigblockdodge]

Follow the lead of the factory, a 5.9 magnum in a 6000#, 4×4 is along the same lines. Decent heads something in the high .400 lift with as small a duration @.050, headers, and a tall dual plane then go spend $500 on a decent converter and enjoy.

 

[moper]

Not to pick a fight but for these types of cams (meaning low end street hp type) there is no difference in chevy, ford, or Mopar lobe. Companies that tout them are full of crap because you can't quicken the rate of opening or closing too much with any stability without opening the valve further. That changes as cams get bigger but those larger cams would be a mistake (IMO) for this build. Low lifts and their respective rates of lift work with all lifter diameters unless you get into custom class racing type designs.
In terms of intakes - the 318/360 Performer is good. The Stealth is a little better given the larger ports. But smaller ports will not hurt this combo. It won't pull hard to 5K. But it will pull like a train until 4K or so.

 

[70bigblockdodge]

So good keep same duration and open the valve further that sounds like a better cam. Lift is free and has no effect on drivability. Faster ramp speeds are benifical to getting you to .300 (arbitrary number) lift and the degrees the valve is held open at or above that is longer, peak lift is not something to solely base a cam on. This among others is the reason why a modern engine with roller cam technology and seemingly not super high lift run so well the valve is open more than half of its lift for a longer period of time. A flat tappet is unable to do this the same way, but looking at ramp speed of the lobe will give you a idea that it is trying harder than a cam with a slower ramp.
Otherwise all the roller cams in the world are making a lot of extra HP on fiction reduction alone.
Not trying to argue either just putting this out there as another way to look at cams. Does the above make a ton of difference that is for someone to decide. Sorry to OP for calling his cam lame but hey its a opinion. Fwiw
Also Comp Cams makes a lot of fine products. They are a large company that has to satisfy a lot of customers so if they don't max out the ramps on a dying technology of flat tappet cams I can see their reasoning. A group of Mopar cams wipes out due to them pushing the limits will make to much bad publicity to justify being the top dog in a meh fight of flat tappet cams. Appeal to the masses.

 

[moper]

I think you misunderstood me. I was only saying smaller cams will get little benefit from a faster opening rate. (Talking specifically of flat tappets here...) So there's little benefit to any cam company to make special .904 profiles for small duration, short lift applications. That was my point.

"Mopar cams wipes out due to them pushing the limits will make to much bad publicity to justify being the top dog in a meh fight of flat tappet cams. Appeal to the masses."
That would be Hughes...lol. Then they blamed the blocks for being poorly machined and worn rather then them pushing too close to the mechanical limit of the parts...lol.

 

[commando1]

Ya know, cams aren't called Street, Street & Strip, and Race, for nothing...
Too many Race cams are being used when the application is a few Test &Tunes.
Too many Steet Strip cams are used to go to Dairy Queen....
Just sayin.

 

[70bigblockdodge]

Yes I agree that it is of little benefit to the cam companies. However it is a quick math problem that will give you a simple larger or smaller number with which to compare.

 

[The Horvaths]

Ya know, cams aren't called Street, Street & Strip, and Race, for nothing...
Too many Race cams are being used when the application is a few Test &Tunes.
Too many Steet Strip cams are used to go to Dairy Queen....
Just sayin.

Hear, hear!