Okay, I have a spare H23 motor, and i'm buying an H22 complete motor w/ a hole in the block. It only had 40k miles on it before it blew. anyway, I'm getting the whole motor because I know I will need alot of parts for the conversion other than just the h22 head. I will be replacig my H23 block's rods & pistons w/ high compression pistons & forged rods (running it n/a w/ a 75 zex shot). I will be replacing valvetrain parts w/ Either Ferra valves, springs & retainers, or crower units. I'll be running the stock cams for awhile, 'til I can afford to buy a performance set after the initial build. My questions are:w/ running high compression pistons (possibly 11.5:1), and running a 75 ZEX shot of nitrous, would it be necessary to sleeve the block? if so, how much does this process cost? the second question...Should I replace the H23 crank, ro just have the stock one balanced to prepare it for the higher rpm? I will be installing the H22's oil jets so it will be more apt to withstand the 7800 redline.