Been down that road before with the 8 3/4 and tore it up badly with a t/brake. 3300lb with driver 67 dart 5000 stall and launch at 3400. had a spool in it with 4.56 gears and 30 spline, twisted the housing and axles. now dana 60 with 35 spline and it hold 60 fts of 1.32 no problem, it just adds about 75 lbs more weight.

Mike