This brings me back to the days of messing with my red-topped '91 MR2... That Glen character that Manji mentioned is quite the source of knowledge with these motors and has (last I read) a pretty nice set-up in his Celica. I know he used to post a bit on the mr2.com forums, but it's been a long while since I've been on there.
I'd like to see an FRS with a blacktop. I'm pretty interested in the weight difference. IIRC when I had the redtop pulled from the MR2 it seemed pretty heavy for a 4cyl engine. Classic Toyota (Yamaha?) iron, I guess.
Also, check this out:
www.beams-redtop.com
Edit: Lots of useful stickies here:
http://www.mr2.com/forums/forums/127-BEAMS-Owners-Group