im building a b17 to run all motor and i dont have enough cash for forged ones. i was think PCT (ctr) but i think that makes it 12.6:1. anyone have input?

 

p30 (jdm b16) or p73-00 (jdm itr) will both put you in the neighborhood of 11:1, but i believe you have to modify the rods for the itr pistions so my vote is p30

 

what do i have to do to the rods for the itrs to work?

 

i did the same thing with my B17 and the best way to go is B16 pistons (p30) compression was like 92integra-r said 11;1 and i used stock B17 rods crank etc. But now it's all taken apart again and went low compression and turbocharged it....

 

Well I know for a fact that the small end of the rod needs to be machined down for the ITR piston to fit on an LS rod, I'm just not positive about a b17 rod. The compression will be basically the same anyway between the 2 pistons.

If I was to do a mild build on a b17 I'd do the p30 pistons and shave a little bit off the head to have C.R. somewhere in the low 11's

You can play around with this compression calculator, it's not 100% but it will give you an idea...
http://www.zealautowerks.com/bseries.html

 

p30 pistons FTW!