I have a stock 85TA rear end, my posi works half the time. I want to get some new gears, was thinking 3.73. I was also thinking of goin the cheaper route and getting a spool onstead of a posi, question is what is the number of teeth i need, and what are the downside of a spool compared to a posi? Thanks

 

biggest down side to a spool, or mini spool is their use is limited to off road applications. teeth in what? there is no sprocket anywhere to have teeth. do you mean spline count? you should have 26 spline axles.

 

A spool/minispool makes for reduced turn radius and the wheels are locked so you get alot of screeching when turning tight at slow speeds.Very hard on tire life when daily driven. If ya drive in the rain it will scare the hell out of ya around corners(likes to get sideways). I can live with mine as it only sees the street about 4-5 times a month.

 

another question. If a get a Ford 9 inch 3rd member, can u use my axels or what would i have to do?

 

The smallest axels for a 9" housing and carrier are 31 spline, a MUCH more substatial piece.
Moser Engineering has a boltin unit to replace our rearends...........I'm gonna beat mine till it grenades then i'll order the Moser unit.

 

i found this ad was thinking of buying it if it would work with my axels?

This is a complete 9" Ford 3rd member with a 373 richmond gear and a 28 spline mini spool. Has little run time on it. When installed all bearings and seals were replaced. I went to a diff. combination so Im selling what I have. 3rd member is like brand new

 

You cant put a 9" center section in a gm housing. Must repace entire housing,axeles,and get a center section(thirdmember).
http://www.moserengineering.com/Page...gaxlepack.html

 

my 85 rear end should be a 7.5 inch right? I got a quote from a place they said labor for puttin in gears would be $325, that seem a bit steep?

 

If that includes the price of the gears and the labor then no. Thats a good deal if its for both----gears are gonna run about $200 alone thats only $125 labor and it takes a few hours to set up a ring&pinion

 

just labor, no parts

 

My guy does it for $200 labor plus parts.