Well, if the benefit of the f23 block is that it has iron sleeves, and a pretty decent size stroke. The down side is the rod/stroke ratio (1.4x). The upside to H22 internals is it's ability to rev higher because the r/s ratio becomes 1.58. The stock compression of a f23 is about 9.3:1. With a stock h22 it's about 9.9 or 10:1. A f23 with h22 crank, pistons (have to overbore) and rods would have a higher compression (about 10.5:1) than a stock h22 and keep the r/s of 1.58. With that much compression, you'd want to get that f23 head to flow better to really take advantage of that extra potential power. If you're boosting, you could find low compression pistons for the h22 and alter the compression. A f23 with h22 crank, rods and f23 pistons (don't have to overbore) would yield a CR of about 8.1:1 and keep the r/s of 1.58. BUT, the piston will be out of hole some, I can't remember how much. So really, it's about budget and how much work you want to put into it. You're right, there isn't that much support for the f23 but I have seen some out there. If I find them, I'll post.