BBillyC
Well-Known Member
Hey guys, I am driving the bird now, but have never had the rear end apart. I know that it is not a posi or sure trak unit in the 489 because when I raise it up and turn the rear wheel the other spins in the opposite direction. When I set one of them down and turn it, two turns of the drive shaft = about 1 turn of the wheel. When I take it to 60mph the tach reads 3000 rpm in 4th gear. I may be wrong but that seems a bit high for a ho-hum differential.
I am planning to redo the rear (with larger tires but don't know what will fit in the wheel well) next year and would like to go with a 391 gear set. However I still need to put in a posi-trak/suregrip. I have been reading that a Dana 60 is the way to go (according to some readers) and I believe the 489 is just as good if built right.
You guys have gotten me through this rebuild of the entire car and this will be the last step, so I am again asking for your most valuable opinions.
I am planning to redo the rear (with larger tires but don't know what will fit in the wheel well) next year and would like to go with a 391 gear set. However I still need to put in a posi-trak/suregrip. I have been reading that a Dana 60 is the way to go (according to some readers) and I believe the 489 is just as good if built right.
You guys have gotten me through this rebuild of the entire car and this will be the last step, so I am again asking for your most valuable opinions.