Ok. I am in desperate need of switching to having a posi rear end. The whole process has been explained to me briefly by several people, just I can't seem to understand it. My car definitely pegs, so I need to know what I need to bye and how complicated it is to install in order to switch. I would like to get 4.10 gears. I don't plan on installing them myself. I am just looking for some guidance and someone to help he understand what is being replaced.

87 Pontiac Trans Am
305 – Auto

 

buy a slp posi unit, a gear set, gear install kit, 28 spline axles and put it all toghter and you'll have what you want.

 

lots of different ways to do it. if you go limited slip, you will at a minimum the limited slip carrier and install kit--probably all new bearings(axle bearings as well). Gears if you want to change the ratio. Axles if you want to run the SLP limited slip. I've had my powertrax locker for quite some time and I wouldn't get anything else. For it you would need at a minimum just the locker--it installs in your existing carrier. Gears/install kit if you want to change ratio(wouldn't go any deeper than 3.73's) Bearings if you want to replace those.

 

yeah i mean i had the original limited slip rear in my car with 2:73 gears and i just couldnt deal wtih it ... so i bought 3:73 Strange Gears and an Eaton Posi and got a shop by my house to do the work and its awesome now ... improved a lot ... good luck with it

 

So does anyone know what size it is, or even how manmy bolts it has and the amount of splines????

 

Hold it a little closer to your monitor so I can count the bolts.

Seriously, it's your car, do a little something to help yourself rather than expecting the rest of us to do it for you, look underneath it and count the cover bolts. That's the first thing you have to do, is figure out what model of rear end is in it. If it's a 9-bolt, then it is (was) a posi already, and the spline count is not an issue. If it's a 10-bolt, and you're certain it's the original one for the car, then it has 26-spline axles.

 

87trans, you should pick your rear end gear ratio depending on what you want the car for, and your engine combination. If you want it as a daily driver, you aren't going to like 4.10s very much, they are too short of a gear for highway use with an auto.

Do you plan on keeping the 305? The reason I ask is because a stock 305 doesn't have much power high in the rpm range. 4.10s would make you go through the rpms quicker, and would keep you where you don't make very much power. Don't be surprised if your car actually loses time in the quarter mile.

It seems like most people like 3.42s for the street.

 

Sorry there RB83L69.
I Apologize I tried to look but my Muffler was in the way. I thought I would ask you guys on the board before I got it in the air. Sorry to everyone else for boldly showing being new to the board, and to this part of my car.

OK.. I am in the process of making a 383. So I plan on having much more power, which is why I need a new rear end to keep from just having that one tire fire. For the most part the car will be a daily drive Plus an SCCA Solo 2 car. And of course going to the track every now and then.

Thanks All knowledge is appreciated.