I've got a B16 block, B17 crank and B17 Crower rods. I'm going to send the block to GE for sleeving and would like to know the best bore size I should run to keep the R/S in the best ratio to keep the original B16's high revving capability.

Also on 93 gasoline, can I use the CP 12.5:1 piston or should I stick to the 11.5:1?

If I run a JRSC on this build, can I get by with the 11.5:1 piston with a good tune?

 

R/S ratios are determined by your crank/stroke and rod length, not bore size. With that crank and engine configuration, reving like a B16 will not be an issue. However, if you plan on boosting, you will not need to rev as high, nor will you make all that much more power at high rpm using a JRSC. Stick with 11-11.5:1 if you're going to boost. Even if you're not going to boost, I would still stick with a comp ratio in that range unless you're building a mostly race motor. 11-11.5:1 comp range is a proven and considered by most to be a more "ideal" comp ratio for best street/strip performance. As with any build, the better the tuning, the more power you'll make and the more reliable your build will be.

 

^ what he said