Ok well I am trying to throw stock parts together to make the most affordable posi possible. The reason that I do not want to spend hundreds of dollars on a posi and gears is because I know this car is not going to make it for enough time to make up for the price. To do this I must ask for some help to help me or anybody else that wants to follow this route.

First off my car is from 1990 and it is a t-5 with a 3.08 open rear, how many splines do I have?

Second off can I just throw any 28 spline posi that I can find including one from a fourth gen?

Last of all the engine is a TBI so would 3.42 better suit me or 3.73, I know that the motor is all low end so I figured 3.42 would better suit the powerband.

Thank you for any info you guys can provide me, and feel free to add on anything that could help.

 

lol I guess everyone buys eaton posi's and richmond gears, somebody has to be able to help.

 

I have looked into similar stuff. I think you can find how many splines you have from teh main TGO tech site, but I have a feeling it's 28. You cant just throw any 28 spline in there though. You need a 3 series carrier. Further, if you're gonna upgrade the gears you are going to have to futz with the alignment of the ring and pinion. Just be aware of that. As for the ratio, I also think 3.42 would be a better all around gear, but it depends on what kind of driving the car sees.

 

The car will be a daily driver and see alot of road lol.

I guess I cant take a posi out of a forth gen then.

 

Yes, you can take a posi out of a 4th gen and install it in your car. The only issue is matching the carrier series to your gears.

 

So it has to be a series 3 then? What is the difference between them?

So far I take it that I need a series 3 carrier with gears that are series 3 as well? When I order the gears does it tell me what series im dealing with from maybe Summit? Thanks guys anything you can tell me will help me make a another quick third gen.

 

Well I believe 3.08+ means it's 3 series but I'm not exactly sure. It's been a while. Anyhow, that's how you tell. And yeah, a 3 series gear will only bolt up to a 3 series carrier. They do make adapters to use 3 ser gears on a 2 ser carrier but they cost a lot.

 

3.08 is 2-series, believe it or not. 3.23-up are 3-series.

On the lower numerical 2-series, the pinion gear is bigger, so the ring gear needs to be farther from the pinion centerline. You can get 2-series gears in the higher numerical ratios, the ring gear will just be thicker. Or, the aforementioned "adapter" which is just a precision shim.

If you are ordering new gears, just order the type that matches your carrier. If the carrier had 3.08 or lower gears on it, you will need 2-series gears. If 3.23 or higher number ratio, 3-series.