I took a look at the part numbers on the pistons and Probe says that with a 68cc heads it will be 9.53 to 1. The clown at the speed shop said it would be right at 10 to 1 when it all said and done. He said he only cleaned up the deck so I figure I am at what maybe 9.7 to 1 at best. Well from what I learned from you guys is that this 294s cam is going to be too for this low comp ratio and bleed off to much cyl pressure. So with this being said ..what cam should I go for?? I will repost my motor specs..thanks guys.

408 sbc
9.6 to 9.7 comp ratio
AFR 195's 68cc
Air Gap RPM
5.7 rods
750DP
1.52 comp magnums
TH400 or TH350
3.42's
Either 1 5/8 or 1 3/4 headers..unknown now..
3000 stall

Here are the cams I am thinking now with the low comp ratio and 3.42's:

Comp Extreme 274.....230/236 487/490 110
Lunati .....235/235 507/507 108
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If your Pistons are 2 valve relief (-4 cc's) flat tops with a 1.425 compression height, and the deck was only "cleaned up" (9.025). Your piston to deck will be .025

With a .039 head gasket, your quench will be .064, this is acceptable but it would be nice to get it down to .045ish by decking the block .015. don't use a steel shim .019 gasket with aluminum heads.

At any rate, even with the poor quench your speed shop is correct, it will be at least 10:1, unless I have guessed wrong and you have dish type pistons.

1/2 a point or so of compression isnt going to make or break a combo unless your going for every last hundreth of a second, you should be fine.

6D9, you didn't say but they must be dish pistons (-15cc), right? I get 9.88 not 9.53 using their quench and gasket bore. Not enough of a difference to make the 294 cam work well. It would run good (7.43 DCR) but it would run much better with more compression (about 10.9). The XE274 would make much more bottom end torque with a DCR of 8.05. The Lunati, if it is the 07102 (285/285 adv) then the DCR is 7.84. A bit lower than I like but it will still run very well. What about the 07101 (275/275)? The DCR is 8.14. This would make a strong runner for your compression. So, just looking at the CR for a cam, I suggest one around 270-278 on the LSA of your choice with an intake closing seat time between 59º and 63º. Given the gears, I suggest a 110º LSA.

Im a big fan of the comps XS series..I think the xs282 would work great...but the xs274 might be the better pick

Thanks guys...so since its only a shortblock right now should I pull it out and go with one of the other mentioned cams ? Oh yeah, they are the -15 cc dished pistons that were spoke of earlier.

Here's the dilemma, Your AFR heads will very much like the 294S cam, but to use that cam and head combo to at least a small portion of their cabability you'll need at least a 3500 stall and a 4.10 gear.
You would have a rocket with a single plain intake, 4.56 gear and 5500 stall. If you go with the xe274 cam it will be much more streetable and a better match to the 3:43 gear and lower stall. But seems like such a waste of those AFR heads.

Originally posted by gatewayracer:
If your Pistons are 2 valve relief (-4 cc's) flat tops with a 1.425 compression height, and the deck was only "cleaned up" (9.025). Your piston to deck will be .025

With a .039 head gasket, your quench will be .064, this is acceptable but it would be nice to get it down to .045ish by decking the block .015. don't use a steel shim .019 gasket with aluminum heads.

At any rate, even with the poor quench your speed shop is correct, it will be at least 10:1, unless I have guessed wrong and you have dish type pistons. Gateway,
There is nothing wrong with using shim gaskets with Aluminum heads. We have used the 1094 FelPro quite a few times on Super late model engines with 13.0 compression with no problems.
Didn't want to use them at first but decided to try them as the person that originally did the engine got the deck wrong so we decided to try them. ran all season with them & when I freshened the engine & redid the block the heads were fine. Minimal surfacing & they were good to go. They did not brinell the head any more than a std FelPro.
The 1094's do require a pretty good Ra though.
Only problem I see for a 400 is the steam holes

Minimal surfacing & they were good to goThat's what I was talking about, the guy has a new high dollar, proud be the owner of, shinny set of AFR's, and the steel shim does leave a slight indentation that will need to be taken down after freshening, that’s been my experience anyway. I agree they can be used, I just don’t recommend it. smile.gif

Originally posted by gatewayracer:
</font><blockquote>quote:</font><hr /> Minimal surfacing & they were good to goThat's what I was talking about, the guy has a new high dollar, proud be the owner of, shinny set of AFR's, and the steel shim does leave a slight indentation that will need to be taken down after freshening, that’s been my experience anyway. I agree they can be used, I just don’t recommend it. smile.gif </font>[/QUOTE]So does the std FelPro.
You left out the part that they didn't brinell the head any more than a std FelPro ;)
It was actually less than the stainless wire FelPro, about the same as the preflattened one.
Took about .003-.004 to clean them to my liking but some think I'm a little anal about this stuff :D

Originally posted by Wolfplace:

Only problem I see for a 400 is the steam holes And the too small gasket bore for a 400. IIRC, the 1094 has a 4.100" bore. AFAIK, there are no shims available for the 400.

Very good point!

BTW, what do you guy's think of the new ROL head gaskets?

ROL Manufacturing (http://www.rolmfg.com/News/pr14-vortec.htm)

I haven't used the ROL so I can't comment.

Excellent point Pat, I wasn't even thinking about the bore size, just the 1094's on aluminum graemlins/clonk.gif