Well its time to order the internals for my motor. So far I have the 383 roller block from summit, Just talked with Joe from A.F.R last week and ordered the AFR 210 heads with spring up grade, and yesterday I got my billet xfi292 cam from comps. My question is what type of pistons should I be lookin at? I was lookin at this set up from summit. http://www.summitracing.com/parts/ESP-B12111030/ My builder told me that the flat-tops 11:1 cr would be to much for pump gas and that i should be looking at a dished type pistion if I ever plan to NOS or boast down the road, which I had thought about but really dont know when. In the meantime I still want a car that rips. Or should I just buy some dished pistions now so in the future I wouldnt have to upgrade if I wanted to boast? I was also looking at http://www.summitracing.com/parts/ESP-B12110030/ Any help would be great. Thanks.

 

With aluminum heads and modern chamber designs, like AFR has, 11:1 is perfectly fine to use on pump gas, especially with a big cam like that one. If you don't plan on using boost in the future, build it as an 11:1 motor and it will be just fine on pump premium. I've run higher CR than 11:1 with iron heads on pump gas and it was still fine.

 

Does your builder know what he is doing?
If he did he would know that Dynamic Compression Ratio (DCR )is the determining factor on how it will run;
not the static CR and DCR is dictated by the cam duration.
Big **** cam like the 292 is going to bleed off a lot of compression so you need a static high compression to start with otherwise engine will be a pig.

Read
http://members.uia.net/pkelley2/DynamicCR.html
Download the DCR calculator at the bottom of page and run your numbers

Note
"It appears that most gas engines make the best power with a DCR between 7.5 and 8.5 on 91 or better octane."



Quick use of the DCR calc from the link above puts your 11:1 383 engine at 8.05 DCR with the 292;
right in the middle of the recommended range

 

Before you buy anything ,
you need to run the Compression calculator and work out your engine.
What cc heads?
How much are you going to deck the block?
What thickness gasket are you going to use?
What quench area? (very important )
Read
http://www.camaros.net/forums/showthread.php?t=124935

Is DCR going to be in correct range based on above numbers and 292 cam?

When you have that sorted you know what size cc pistons you need
Depending on what size pistons are available off the shelf may have to move deck / gasket numbers around to get desired result
Much easier than buying the pistons 1st ; then trying to juggle the other numbers to get what you need