Let me just run this past you guys....I'm helping a long time mate who's running a street/strip '70 Challenger, more strip than street motor wise, weighs approx 3800lbs, all steel, with a 440 thats making around 550fwhp on track as he's run 121mph@11.06 with 1.56 60's.
Motor spec is approx 10.8:1, ported Eddy heads, .583 SFT cam with 1.6 rockers, don't know duration yet, M1, +1" spacer and an 830cfm DP....just had the 727 rebuilt with all good parts fmvb, and just put in a used TCI 10" super street fighter verter (142222) that he says flashes close to 5k on the hit. The cars picked up .5 sec in ET so he's well happy.

Issue is that inputting 550hp into wallace with 3800lbs, 3.91 gears and 28" slicks it comes up with 11.06@121 with a 1.54 60 BUT at 5678 trap rpm+slip, he's hitting the limiter at 6500 in the traps, pushed it up to 6700 and still hitting it and he says its still pulling, thats 20% slip!!!...what do you guys think may be going on here, any thoughts....weight/gearing doesn't help I know but if its still pulling is he blowing through the verter?, I doubt it re the good mph. Should've had a race verter built he says, he's right.

cheers.