Can I put a SLP POSI takeoff unit on my stock rear on my 92 RS ar do I need different spline axles?

 

What gears do you have now? If you have 2.73s, you'll need different gears. SLP posis are for 3.23 and up gears, better known as 3 series.

To answer your question, yes it will fit. You already have 28 spline axles.

 

I do have 2.73's but I want to get 3.43 or 3.73 installed at the same time. So will I need a ne carrier?

 

the SLP posi unit is the new carrier. I have a 90 RS with 2.73s, and within the next month or two, im plaining on installing my SLP posi and Richmond 3.73s. Just remember you also need an installation kit that runs around $100-120. IM probably gonna go with the Deluxe Ratech kit that runs 120 in summit.

 

A little confusion here. I've read mixed answers on which cars got 28 spline axles. Some say 89 and up got em. Others say 89 and earlier don't have them. So which is it? Or do some 89s have them and some not? reason I'm asking is because my friend has an 89 RS, and we're trying to figre out what mods we want to do to it for he best bang for the buck. The SLP posi and some 3.42 gears are high on our list, but if he has to swap axles we have a problem.

 

With a 89 car, you never know. 88 was 26 spline for sure, most 90s are 28; but 89 is a mixture. There seem to be more 26s than 28s from people's posts here.

Definitely look before spending money.

 

What do we do to figure out if it's 26 or 28 spline?

 

I would like to know too, i have a 90 RS so i should have the 28 spline rear but this post is getting me kind of paranoid.

 

Pop (well, unbolt, you know what I mean) the rear cover, remove the pinion shaft lock bolt, remove the pinion shaft, remove a c-clip from an axleshaft, and take the axleshaft out. I don't think the axleshaft splines are visible unless you take 'em out.

 

yup...take an axle out and count the splines.