gears and diff are in, and the bad news is...
 

got my 3.55's and a new diff installed but while it was apart the wrench noticed that my axles were grooved really bad at the outer end. So... I said screw it and ordered a set of Superior axles. Those should go in next weekend.

Fortunately I can install those myself. Should take me a good hour or two.

Before you start on me about not going to 3.73 or 4.10's, the 3.55's are my personal favorite for the modulars. They put the exhaust note up where I like it for cruising at 70-75mph and they don't make first gear useless. I'm happy with them.

I'm really thinking about a 9" now though.

did you just get 28 spline? i dont see why 31 wouldnt be a great upgrade since axles have to be ordered anyways. You can get 31 splines from the trucks, get carbon rebuild kits, and have a superstrong rear end for a decent price.

I dont know anyone who has broken 28 spline units. carries yeah, but axles no.

the diff that was available at the time was a 28 spline... so I stayed with 28.

I know of 2 instances of people breaking axles and both were on slicks. On street tires... there's no point. Apart from that, I'm putting in pretty darn tough axles so I ain't trippin over twisting one.

In any case, it's a little peppier now and I've loaded a new tune for the gears (and a little tinkering on the fuel trim). Things are coming together slowly but surely.