Stock 60s are really stout. A friend is running low 8s with stock type gears and a spool.
Whichever way you do it, it pretty much takes the rear end out of the picture as far as worries, until you get to mega hp with huge gobs of nitrous or boost.
R.
In the Ramcharger, I am running stock 4.10 gears, a Dr. Diff spool, Dutchman 35 spline axles, Torino ends with Ford sealed bearings and a new Ford racing 11" drum brake kit. I had it professionally narrowed on a jig. I built it from a Dodge truck rear that I traded for. And I have about $1,600.00 in it.
I also built a Dana 60-2 for the '87 D100. It came with a PowerLock, stock 35 spline axles, 4.10 gears and rebuilt 12" drum brakes with 5 on 5.5" bolt pattern for $400.00 out of a yard. I had to narrow it 6" on the left tube and axle, respline the shorter axle and have the housing professionally jig welded. I have about $900.00 into this one.
Bargains can be found, you just have to look.
