7.5 posi and carrier swap- how far do i really need to go?

[Silent viewer]

I have a stock 7.5 sitting here as a spare right now, I have a posi carrier out of a 82 regal, a set of 3.42 gears out of a bravada, ring gear spacer and a rear disc brake setup from a Camaro. The car has a mild 355 chevy and th350 transmission being used for street use only. I am wanting to get his carrier and gear set swapped in but I have never done a rear end before, I have rebuilt just about everything you can find on a car including multiple engines so I think I can knock this out. I know I can go balls to the wall on replacing everything inside of this thing but I am not sure its worth it on a car that may see 1000 miles a year and may have a 8.5 in it in a few years. I am thinking about replacing only the seals and crush sleeve and reusing the existing bearings, does anyone see an issue with this? I have been building g body cars for nearly 2 decades, I have parted out 20+ rusty g bodies, personally owned and driven close to 10 of them and have yet to see a bearing failure on a rear end even cars with 250k+ on them so I don’t really see an issue here. most of these parts are from low mile vehicles and I am guessing that the OEM parts are likely better quality than the over seas crap that parts stores stock anymore. am I being an idiot here by not replacing these parts? i would rather put 200 bucks into something else on the car

 

[theoldsone]

I myself have done the 7.5 posi/ring gear swap. Using a used posi carrier from a 2 series 7.5. But I bought new 3.73. So yes #1 find out what carrier series you have. Either a 2. Or 3. Your Olds should have a 2 series housing which would accommodate a 2 series carrier. And scince you say you have a used ring gear i would see what series is it for. (Part# search). You should know that if your planning to change the ratio you will need the ring and pinion, not just the ring. One other thing using a used ring and pinion is IMO a bit risky. In a new R&P They lap the two using the correct back lash and depth before they sell it. So using a used ring and pinion on a different carrier will require you to set the backlash and pinion depth. But depending on how the pinon wore to the ring gear will be exactly how you want to set them up. Its alot of work. All in all probably not worth the hassle. Buy a new ring and pinon. Shim kit from youkon, pinion shim and bearing, lube and gaskets. I spent a total of around $300 bucks rebuilding my 7.5 posi. And i did all the work my self. Oh not including the tools needed. Hope this helps some.

 

[axisg]

IMO for all the hassle it was worth it to me to find a decent rear from a Monte SS with the 3.42 or 3.73 already in there. I sold my open 3.42 for $ 150 and bought a posi 3.73 for $300. If I dig into a rear its going to be an 8.5 or 9"
Plus I had the time to clean and paint my new rear before it went in ( should have done the rear disk then too

 

[RegalBegal]

I did my carrier swap 5 years ago and re-used the bearings... no problems at all. Clean them good and make sure the races are good. The 7.5 will hold up fine for street use. FYI... 2 series carriers go up to 3.08, 3 series are 3.23 - 4.11. you can tell the difference by the ring gear flange.

 

[lilbowtie]

Ditto the Begal - You'll see there is not much to it.

 

[Silent viewer]

the carrier is a 2 series and I have 3 series gears which is why I have the ring gear spacer. i have had bad stories about ring gear spacers but i have also heard of people that have had been running them for 20 years with no issues. i am not racing so i would imagine that it would be just fine. i am pretty sure i am going to go ahead with this swap as planned since i have everything sitting here. thanks for all of the info guys

 

[LioFR]

Anyone know this product ?
Probably can it fit in your rear axle? i know you already have the gears but i think it's more secured than a spacer (in my mind lol).

i have the same problem like you with my 80' Cutty and i think this product could be the good solution for us.....

http://www.strangeengineering.net/d.../motive-gear-gm-10-blt-7-5-3-42-2-series.html

If you think it is bullshit.....just say it lol