Ok, so this is one of three die-hard "Naturally Aspirated" F23A1-VTEC builds happening through 6GA forum. Everyone has something different they're trying out; thanks to AFAccord again for his feedback & shared info. Mine kinda took a different route thanks to "michaelp4283" (200whp or bust) who supplied the piston kit: Forged Wiseco 86.5mm (-5) piston and ring kit (custom) Compression will be about 10.69:1 KaizenSpeed "Balance Shaft Eliminator" kit installed. Crank was balanced, of course. The head is another fresh one I picked up locally: No milling Ported intake & exhaust to match stock gasket Bisimoto Valve spring kit and stock valves and retainers. Flow tested head @287cfm. I'm also using the same WebCamshaft (custom regrind) that was used to dyno car last time. The intake is an F23 ported to match and the upper TB/Housing was also ported to match my 68mm TB. Basically, more compression, no balance shafts, home-made intake/head work and spring kit. ???whp - we'll see soon! Updated 2/16/10 UPDATE: 2/17/2010 - 171wtq/174whp For those who still wonder (=200tq/203hp) at 17% drivetrain loss. The gain is from the green curve to aqua curve. I gained a bit over 20whp and 18wtq. Basically, my intake is all out of vacuum and restricting flow. My fuel is already at peak so if I change my intake or modify somehow to flow more, I'll need injectors and fuel pump. For now, it is what it is. I/m happy with results. The engine wants more so that's a good thing, more room for improvement. Thanks for following up with this thread everyone, I hope it helps shine some light for a few and helps others make other improvements. Here's a peek! http://www.youtube.com/watch?v=R6Z-x0MUc1c Good luck to everyone else trying to pull max ponies out of these motors!