[jdmerk]

oh yea ive also heard really good things about rhoads lifters...increasing low end torque and vaccum with radical cams, whats your take?

[JKGTO]

More info needed on your combination. What converter, gear ratio, tires stock or larger? If possible you might take the engine down to the shortblock to see what you actually have now for a cam and pistons and CC the heads to figure out the compression. You are going to have the intake off anyway so you may as well take off the heads to check things out. All the parts have to work together with the cam. Jim

[jdmerk]

running 26" tires, stock converter, 2.73 open gears in it now...soon to be 3.55 or 3.73 with a locker. so im gonna need to pull the heads while im in there? ok, but how can i tell what the CR is jsut by the top of the pistons?

[John Milner]

If your engine has flat top pistons in it, I would look for a set of 16 or 62 heads to get about 10:1 compression. If you switch to 3:73's I would look at the summit 2802 cam (224/234 .465/.488) or something like the crower 60916 cam (221/229 .455/.470). You may also want to look at getting a higher stall, something like a 2500rpm. Either one of those cams should have a choppy idle. If you want a nasty idle I would look at the comp XE274 or the Ram Air 4. As for rhodes lifters, I am not a fan of them because they are noisy. But, if the noise dosent bother you, I am sure they would work well with a bigger cam.

[jdmerk]

how necessary is a higher stall on those cams you listed? also hows the vaccume on those choices? and can the 6x heads handle that lift?

[John Milner]

I have ran the Summit 2802 in a 400 with 10:1 compression. I was running 3:23 gears at the time, and it had plenty of power all the way to 5700rpm or so. I also ran a stock converter. It had plenty of low end torque to smoke the tires. I'm sure it would have ran a lot better with a 2500 stall and 3:73's. I am not sure on the vacume, but it had plenty to run the power brakes. I would say that if you switched to 3:73 gears you could get away with either the crower 60916 or the 2802 with the stock converter. If you ran a ram air 4 or the xe274 you would need a 2500-3000rpm stall for sure. I would invest in a new set of valve springs. Also, unless you are running a domed piston, the 6x-8 heads on a 400 will yeild around a 7.6:1 compression ratio, a 6x-4 head will yield an 8:1 compression ratio. To run any of the cams that I suggested I would recommend atleast 9.5:1 compression, with 10:1 being the best.

[jdmerk]

ok so your saying i need to switch heads to make this worth my time...which stock heads would net the type of compression your talking about (provided i have stock pistons)