Here is the deal though, the actual bore of the h23 is 87mm, and my block just got bored out to 87 for my new forged pistons, my stock block was 86.32 mm before we bored it, and I have the rods for an H23 already and the rods, I am thinking the pistons I have won't work probably but I can get H23 pistons off the shelf and shipped in a few days, however if I go with my F23 I will have to get customs rods since the specs Honda gave me were wrong for the F23 so I have the rods for the H22 and some for the H23. And now that my block is already bored out I can't use my stock internals but I need to get my car running as soon as possible so I am trying to figure out the fastest way, and the H23 rod bearings are bigger so THat will be better fot engine life. I am just wondering if the block will bolt up, my mechanic is very experienced with LS/Vtec so that shouldn't be an issue. Thanks for any other help.