I just got a posi with 2.73's and the seller said it was a 10 bolt from a '89 T/A. I want something a little quicker, maybe 3.83's or so. This is going to be my commuter car, 60 miles of highway a day. Gas money isn't an issue, but I don't want to run my engine at too high an rpm and damage it. Should I get something a little more tame? Also, is there a way to confirm the size of the replacement gears I'm going to need without opening it all up to measure? and last, is this as simple a swap as people make it sound?

 

1) you probably mean 3.73s, cause the 10 bolts never had or have 3.83s to my knowledge.

2) I did my swap having never done one before. Went easily IMO, but was timely b/c I was using it as a learning experience. I didn't think it was hard to do, and would never have anyone else setup my gears again, unless I couldn't possibely do it myself.

3)I put in 3.42s in mine and run about 70 miles an hour around 2250 RPM. Maybe a little less. My buddy w/ 3.73s is only about 250 RPM higher than mine in OD so those won't be bad at all IMO.

If gas money isn't an issue then the 3.73s will be what you want. I wish I had gone w/ them in my swap. And no its not going to hurt the motor to be spinning that high. The sound of it spinning that high through the exhaust may make you cringe but I think you will be ok!!!

 

Go with the 3.73s. It's a great gear.

To run 3.73s in a 2.73 rear you need the thick gears sold by Richmond to adopt a 2 series carrier to a 3 series gear. Or you can use a ring gear spacer and longer bolts.

You need a 7.5/7.625" 10-bolt gearset. They are all the same. If the cover's got 10 bolts on it this is what you need. The gears are the saem for all years.