have an 89TA with rear drum.. and 3.73's
anyway

I dont have the cash to fork out for a 12bolt or 9in.
looking for something i can do. will an aftermarket cover help?

was kinda hoping to slap on a set of cheater slicks and do a couple weekends.. nothing too serious.

 

Yes the cover will help.

No it will not cure. Don't be too surprised if the rear grenades anyway.

Other "cheap" things that will help (but not "bulletproof") include welding the tubes all the way around; and using studs for the carrier caps instead of the stock bolts.

 

are there any sources for rears other then aftermarket?
all that i can find is that latemodel fbody rears fit but are no better.. except disc brakes.. but need late model wheel offset.

 

Its possible that it'll last until the low 11's, but don't count on it. Keep your foot out of it until you can upgrade to something better, or save the money from a cover and buy a corporate 8.5" from a 2nd gen, then mod it to fit. IMO its the easiest and cheapest swap out there.

 

low 11's? i wont be getting there anytime soon.. i'll be working in the 13's .. its a shame these cars didn't come with something that had a little more snort..

for welding the axle tubes, is there anything i have to do? or can i just fire up the mig and lay a bead all the way around without removing anything?

 

The only other diff that will bolt into a third gen other than from another third gen is a fourth gen diff. They're not that much stronger. At least the 1990 and newer f-bodies have the larger 28 spline axles but they all have the tiny 7-1/2 or 7-5/8" ring gear. Downside of a fourth gen diff is that it's 2" wider on each side. You need rims with a different backspacing and from a performance standpoint, longer axles are easier to twist than short ones. 2" might not seem like much but it will make them twist more eventually.

Trying to adapt a non bolt in diff could cost you more money that a new aftermarket diff by the time you're done.

Drive what you have until it breaks then decide how much you need to spend. Stock diffs can break on the street with a V6. Stock diffs can also survive dragstrip use into the 11's with no problems.

I switched from a beefed up 10 bolt to a 9" when I installed a transbrake. I was running low 11's on the 10 bolt but it wasn't considered stock either.

 

Its much easier than everyone thinks, lots of measuring and some time with a drill press and an angle grinder and you're in business. I did the swap into my old 4th gen using a stock 77' Firebird 2.73 posi rear.

For only going 13's I wouldn't worry, plus I see you have a T5, so you have much more to worry about than the rear exploding. And axel welding won't do you much/any good, not like your power level is going to break the spot welds any time soon.

 

going to a t-56.. its on the floor in the garage .. but not like that is going to increase the power.. also thinking of getting a Alum driveshft out of an LS1. but again.. not going to increase the power.. All I want to do is bolt on a set of slicks and stand a reasonably safe bet that when i let the clutch out and come on to it.. that the rear will not explode.. im not going to drag the car.. just 1 or 2 trips a year .. running basicly stock. headers and 1.6:1 rollers. Anyway.. by the sounds of it.. stick with the 10bolt, get a cover as a little insurance.. and beat it until it breaks.. then upgrade..

thanks.