research balance shaft removal. Don't get the kit. we installed the "balance shaft removal kit" on a freinds 91 eclipse it consisted of a few gaskets and a little plug that was supposed to spin in the oil pump. there were no oil passages in the plug and it quickly seized up and destroyed the oil pump. and may have contributed to throwing the time out and knocking the pistons into the valves..i say may have we aren't sure. but at any rate, cut the end off of your balance shaft and use that. (a side note..Its absolutely crucial to get the engine timed correctly, if not pistons hit valves and you have a bad day.)
they sell cams, headers cold air kits all of that, but when its all said and done you have an expensive engine making mediocre power.
if you really wanna put some gitty-up in your get-along get the engine and transmission from a FWD turbo eclipse talon or laser and toss that in. then upgrade the turbo and exhaust.
the DSM engine...for a 4 banger doesn't do to bad, when it works. But to to give you an idea of the reliability...I've personally had the engine out of 3 different cars 7 or 8 different times. and i don't even own one.