28 vs. 31 spline axels

[jerry S]

I will be replacing the stock differential on my '69 Mach 1 with a Detroit Locker. I am currently at 325 rwhp behind a C-6 and that rear wheel number will climb by about 40 hp once the heads and intake are ported and the new carb goes on. I will also be adding a 125 shot of nitrous. The car will see a drag strip about 6-10 times a year with about 4-5 runs per event. Do I need 31 spline axels with the locker, my level of power, and the kind of racing I plan on doing or can I get by with 28s?

 

[eagleautosports]

I think it'd be a good idea to go with the 31's. You'd be at the limit of the 28's considering what you plan to do with it and better to be safe than sorry.

 

[Max Power]

While you are in there and buying new parts, I would go with 31. With the automatic, you may not need em, but if you find out otherwise, you would have to redo the diff. Why risk it?

 

[dennis112]

You might be borderline on needing them using street tires. You certainly should consider upgrading before hitting the NOS with sticky drag type tires.