Ok so Im about to pick up a b18a block for 200... Now Im considering rebuilding the block and putting in p30 pistons on my ls rods and polishing the crank... Or would it be a better idea to get either standard or oversized itr pistons? Would gettin the oversized ones make alot more power? Also anyone know the cost of blueprinting and balancing a block?? Thanks alot guys.. Any info would help.

 

Oversized pistons are only .25 over... they are used if your cylinder walls are scratched, or very worn. If you have a stock block thats never been abused, or doesnt have 200k miles on it, I would just hone it enough to break the glaze, then slap some pistons on.

As for which pistons to get, in order of highest to lowest compression
(this is with PR3 head w/ b18 block)

CTR pistons=11.9
P30 pistons =11.5
PR3 pistons =11.32
P73(JDM) pistons =11.31
P73(USDM)pistons=10.8
P72(JDM) pistons =10.5
P61 pistons =10.01
P72(USDM)pistons=9.98

As for CTR/ITR they have that special molyblahblahblah teflon lookin stuff around the side of the piston that is supposed to reduce friction. Anyway, the cheapest route is P30 if u can find them, or PR3 is a good route. If you can get your hands on a set of JDM ITR used pistons that arnt over priced, then that isnt bad either.

The cheapest most cost effective bang for the buck is pr3 or p30 pistons.

 

do the ctr overbored pistons
get arp rod and head bolts.