I'm trying to find an affordable option for forged rods for the F23. It's been well established that K20 pistons can be a direct swap, but what about the rods? Here are the specs for both Crower's K20 and F23 rods: Part #.........Engine.......Length.......BE bore......BE width.......PE bore........PE width B93749B-4.....F23..........5.551........1.890.........0.780........0.866(22mm)... 0.780 B93733B-4....K20A3.......5.453........1.890..........0.780.......0.866(22mm)... 0.780 As you can see, the only difference is in length. The K20 rod is .098" or 2mm shorter than the F23 rod. I'm trying to answer two primary questions. 1. Would the shorter K20 rods have the necessary vertical clearance in the F23 block, primarily at the bottom of the stroke? 2. Somewhat unrelated, what is the correct way to calculate the compression of pistons rated 9:1 for the K20, when installed in an F23 block? I've been playing around with Zeal's compression calculator. Even if I tried to use the K20a3 forged pistons at 9:1, that wouldn't give me a 9:1 ratio with the F23 block and head, correct? The shorter length of the K20 rod in the F23 block would drop compression down considerably, right? The stock K20a3 piston @ 9.8:1 should have a -2.5cc dome from what I'm reading, while the off-the-shelf wiseco's for the K @ 9:1 should have a -8.3cc dome according to the calculator. Now if I used the K20a3 rod in the F23 block with the stock F23 piston, my compression would drop down to ~8.14, which I assume would be way too low to be practical on a street car. However, with the off-the-shelf Wiseco K20 piston at -8.3cc (per my calculation), compression would be up to ~8.69, correct? At this point, couldn't the head or block be safely milled or decked around 20-thousandths to bring compression up to almost an even 9:1, or where ever I wanted it to be? This doesn't take into account that the F23 combustion chamber is .5cc down from the K20's. Are there any obvious flaws or drawbacks to my logic? Is it possible to use the shorter rods with this block? I'm by no means an engine expert or machinist, so just slap me if I'm wrong, but please elaborate as to WHY this wouldn't work.