further to mungyz suggestion what you could also do is fit a gts4 diff which has a 4.3 ratio - na cradle - gts4 diff - tt driveshafts or alike - machined spacers for the driveshafts to fit
Mine is n/a > TT still running n/a diff. 2860R turbos. 1st even more useless in TT than n/a way too short 2nd :br: 3rd:br: 4th is still a blast 5th will still make boost at hwy speeds never need to drop back a gear. Haven't driven a bog stock TT but from those who have and then converted to n/a or leader gears I think I'd take their word for it. Zed needs a 6 speed box then it will be sweet.
4.3 is too short . slotcar did 10.7 with 4.3 but crossed the line in 4th around 8500rpm . with 4.10 it still runs out of puff at eastern creek before the end of the straight .( .83 5th gear).stock 5th would work . 4.10 is quick but still has legs on a built motor that makes power to 7500rpm .
