Okay lets start this out with 1999 RS Eclipse 2.0L DOHC

Looking to tune to 350 hp only

waste time on the engine currently or just upgrade to the 4g63?

Just buy an ls1

Get the 4g63 or an LS1, make you get the non crankwalk one if you pick the prior.

I think its the 7bolt that is affected by crankwalk

Figure out the bore and compression of the gsx and have some forged internals made for your rs, throw on some new seals, and air intake along with new headers and then.

buy a stage 2 clutch and tranny rated for 500hp, invest in a 45 mm turbo at 8-10 psi for daily or 20psi for weekend fun.

Dsms need all the help they can get.