Rear end question

[T/racerX]

i need to know what type rear end i have on my 84 T-Type.10 or 12-bolt,7.50" or 8.50" ,and how many spline i my axle26,28,or 30.So i can lock my rear end up and get rid of my peg leger????????

 

[WFO]

the stock rear end is an 8.5" 10 bolt.i believe the stock axles are 28 spline,but don't quote me on that.

 

[GNeric]

WFO is correct. In 89 they changed to 30 spline in the 8.5's. Look at the bottom of the diff housing. If there are two "square" lugs, it is the correct 8.5. If it has what looks like two "fangs", it is the incorrect 7.5.