Chip, I just fitted coilovers on mine, and does require some very minor mods to the inner arch where the bottom of the spring will sit. Mine had about 2mm clearance, but after 5 mins with the ball pain hammer, has about 5mm.

My Stage 3 was simply T34, on greens, 7.8:1, about 26psi, on konis, standard rear end and diff/clutch etc. I think the terminals were about 110mph.