I would guess that the JRSC on an SVT would definitely need the race gas on the track. High compression ratio and hot inlet charge - bad combo! Glad to hear it still works for you tho.
My first pick for S/C would be a PW SVT because of the intercooling of the PW and the forged internals/oil squirters of the SVT engine. But if I used a ZX3 with an intercooled PW, I assume the motor would be okay for track stuff but still more susceptable to track-stress issues than the SVT motor???