A 90 Si, everthing stock in motor except for a "mild" cam (about the cam...don't ask!). This engine has just over 185K miles on it. This little 5 spd monster is lots of fun. I am willing to keep it for another 10 years. The entire exhaust was modified; 4-2-1 headers, high flow cat. and muffler, connected with 1 3/4 inch S.S. pipe. This gave significant performance gains even though mostly at the top end. Possibly due to high milage and my "spirited" driving I find black soot-like deposits accumulating around my tail pipe. I am now considering the big swap. I want good bottom to mirange performance...I dont have too many chances to run at 250 mph. Need some real world experience...the shops around here are afraid as soon as I mention swap. I have gone through the FAQs and realated Articles and I am now alot more educated but lacking direction. Any advice would be appreciated!