connecting rods.

I can't speak for everybody - but I had 2 sets in the same motor and killed pistons both times. The problem is that they do all thier expansion on the top of the piston, as opposed to the entire piston growing - like a forged piston does. Since the KB's make an advertised 10.9:1 compression with stock heads they tend to have a little detonation problem - translation: they don't like pump gas. Mine did fine until you ripped it good and hard, then the spark arrived and I had to get off the throttle. Problem is that the detonation has to be pretty bad for you to actually hear it, so by the time you do the damage has already begun. I tried everything to kill it - bigger exhaust, bigger cam (more overlap), smaller cam, better fuel, less timing, more timing, bigger carb, smaller carb - nothing got rid of it completely. Of course, by the time I got it somewhat managable, the damage was already done. So I went through the motor again (new set of pistons) and started over. the combination was different and the detonation was significantly less, but still there nonetheless. Piston expansion is what killed the first set - the top of the piston expanded and bit onto the ring and blew the top ring lands off two of them. I don't like them. By the way, that motor was a 360 also. Obviously lots of people don't have problems with them or they wouldn't still be selling them - maybe my experience was an isolated incident - don't know - won't try it again. If you can knock some of the compression out of them - get it down to about 9.5 or so they would probably be fine, and the motor would still be a terror. Sorry - it would appear that I'm rambling on. I'd spend the money and get the forged units or maybe something from Ross...