ok so the weakest link is the head right? What is a good choice for a head? Both ends will be ported, I'm running a aftermarket can (sounds good "only"). top gear dropped by 2, going up 1 soon. EPI clutch, and an 1.25 track w/144 studs. my main riding is ditches but I hit top end enough on the lakes and fields to be an issue. i always try to run atleast 90 octane (in minnesota and the U.P. mainly) The sled must be reliable! What is a good head to run? i do not know I will be running for pistons/rings yet, are they worth swapping? The sled has 2,200 miles on Amsoil all it's life. Compression is 145 on a cheap Craftsman gauge. oh, and new reeds or also cages will be added.