mjr46

you don't want to switch to the cobra style pocket bearing, iirc there is something different about the output shaft, when I called the gear box.org and spoke with Kevin there (he is a master with anything t-5) anyway, I think and don't quote me, he said I would have to source a used output shaft from the cobra spec to work with the pocket bearing since the tip on the stock output shaft is set up for needle bearings riding on it's surface where as the cobra style fits in a pocket bearing/bushing, iirc he might of told me you could machine the tip of a oe output shaft to work but long story short, it was going to be a pain to add that set up for the relative small gain in strength it adds., but I may be off on this info, as this was a few years ago I was contemplating doing this, I finally just went with a tremec 3550.

wydopnthrtl

Got the rear end out today.

At what level of tire & launching rpms should a guy step up to 31spline axles?
I'm really temped to go w/31s and a detroit truetac. But if I did I'd be looking at an extra 800 bucks.

Are the 28 splines (stock size) good enough for ET streets and 5000rpm launches? If not.. what about DRs and 3500 launches?

Tony71502

Not really sure on their strength. I had to get new axles when I went to 5 lug so I got 31 splines at the same time. Despite metal properties and QC and all that junk... can't really tell what they are rated for until you break them.