Your #1 mod should be the track, the 670 has the power in stock form to turn a longer track. Go to at least a 144x2 but a 151 is better, I up'd to a 144 first and then the 151 and both were a big improvment over the one before. The next thing would be handlebar riser and ski's and you'll have a very capable mountain sled. Good luck and post pics
As He just said!!!!!!!! do your track, better skis, riser for them bars and you will have perma grin!!!!! The folks here are great with info ,,,and look at 99summitx sled..that ol s chassis looks awesome.....Great job Kelly!!!
and not to steal your post but thanks to Kelly (99summitx) and others on this site........heres how my 98 summit x turned out....I freakin love it!!!! First pic is factory form and 2 more is what ive done...sorry for crappy pics!! lol
Have fun and get ridin..............Bri