Hmm....I just checked mine and could not find any obvious indicators (extra numbers or stickers or anything). I popped the cover and can read nothing in there. I guess just performance and data logging may be able to tell you. The obvious would be (as you alluded to) checking the redline.
Captain Caveman
96 RS Turbo 11.414 @ 119.62 MSNS, Crower 2 NA cams, BW366, 10.5 comp, UDP, 60mm TB, W/A intercooler, 3.55 tranny 567.9whp 430tq 97 RS NA 13.188 @ 103.87 MSnS powered 12.5 comp, Crower 3's and 219.4whp with 175tq 98 RS DD 12.5 comp on stock ECU, LTH, Crower 2's, Koni, GC, Hypercoil, DG hats 99 OZ 5sp Stocker 15.856 @ 85.97 99 GS stocker auto 17.7@77mph!
