So, uh, why would you want to swap in anything else?!? The Lampredi Fiat engine is quite possibly the best 4 cyl engine ever built. What else ya gonna put in there that will run all day long at 9000 RPM?
My old 124 Coupe with a fairly mild 1608 was a pretty potent 5.0 Mustang killer in the early 90's. If I couldn't take them in a straight line, I'd lose them in the first turn. (9.8 compression, dual 40 IDF Webers, 300 duration cams, 21mm timing belt)
