I just finished the mod's on my 85 GT. I want to dump the 7.5 rear end for an 8.8 and am undecided on how strong I should build it. Without dyno testing the motor I'm guessing I have around 300 RWHP. The car also has the factory T5 trans. If I go with the 28 spline axle's I will save about $300 as I would still be able to use my stock one's. I've been told by a couple of seasoned racers that the 31 spline would be over-kill and to save the $300 to spend on something else. They say I just don't have the HP to justify the 31 spline. Also, because of the highway miles I drive would I be smarter to go with 3.55 gears or 3.73? Running the stock 2.73 now and spin the tires pretty easy

 

I agree with the seasoned racers.
________
Colorado medical marijuana dispensaries

 

yeah...keep it a 28 spline

 

I've decided to go with the 28's. The used axle assembly I picked up has a good differential, so that makes it easy for me. All I need is the 3.55 gear set and bearing kit.

 

I think that you made a good choice.