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I am trying to figure what pistons you have, so a few more questions?
Do you know the piston manufacturer name?
How many valve reliefs 2 or 4?
Are they Cast, Hypereutectic, or Forged?
At TDC does the is the top of the piston above or below the block deck? and by how much?

To figure true compression ratio, do you know what the measured cylinder head volume is?

And last one, which head gaskets are you using?

Here is why it matters, your compression ratio could be as high (or higher) than 10.85:1.
The 10.85:1 number assumes using the Keith Black #243 piston, a 65cc cylinder head volume and a 0.020" thick head gasket.
On the low side, the compression could be 7.95:1 using the Speed Pro ZL2385 piston, a 72cc head volume, and a 0.040" head gasket.

From looking at Summit racings prices, it looks like the most affordable piston would be the Federal Mogal Z428P30 piston at $31.69 each?
This is a cast piston with 4 valve reliefs, and should sit 0.007" above the blocks deck.
The description did not have the valve relief volume listed, but from the other pistons with 4-valve reliefs it should be about 7cc?
So this piston with the theoretical 65cc head, and 0.020" gasket should give you 10.41:1 compression.
Just switching to a 0.040" head gasket will drop the compression to 9.88:1 compression.

Cams:
Hughes Whiplash HMC2336AL 223/236 @ 0.050", 0.512"/0.518", 107 LSA.
Hughes HEH2328AL 223/228 @ 0.050", 0.506"/0.524", 111 LSA.
Hughes HEH2832AL 228/232 @ 0.050", 0.524"/0.540", 110 LSA.
Lunati Voodoo #60403 268/276 Advertised, 226/234 @ 0.050", 0.494"/0.513" 110 LSA.
Comp Cams XE268H 268/280 advertised, 224/230 @ 0.050", 0.477"/0.480", 110 LSA.

I think any of the above cams listed above should work decent. If you like the sound and rough idle, the whiplash would be good. The wider LSA of the HEH2328AL would give a nicer idle.
The HEH2832AL is getting big for your converter/gear, and may punch the pushrods through the stock rocker arms.
It looks like the lobe profile of the comp cam may be less agressive and might be easier on the valve train.
The Lunati cam would probbably be my choice, mainly because it looks like it might be the least expensive. It also looks like a really nice cam, at least on paper?



At this Time I don't know what piston he is using brand etc?.. Going to try and find out. also I told him to CC the J head just to see where its at. The thing with the cam we Already have the 4452992 cam ,bought it last week. So that is the cam we have to work with. So I guess until i get more info from the builder we will have to figure out the best ICL and not make a ping motor! I thought 106, but now I see someone says 102? Man this thing won't even idle very well at 102 will it? I totally appreciate u working with me on this and welcome your help as we go along here!.Also When he bought this car he thought he was getting a nice restored car! well the motor was junk, trans junk, needed a dash harness!. The guy obviously lied to just sell it and it was not a cheap car either! if u would have seen the car u would have thought there was nothing wrong! everything painted nice and clean etc! I just want my brother to be happy and not have any problems with this new build!
One other thing this is my older brother's car and I am helping him the best I can AS i know pontiacs not mopar, so that is I why appreciate all help from everyone here!

Last edited by menomoniemopars; 09/23/10 11:19 AM.