How far to push 28 spline axles?

this is a good question. some people say that they snap them with DRs and about 270ish hp. others say that theirs are still going strong after a whole bunch of passes with DRs and 4k launches.
why not just get a 9 inch rear?

Im running 28-spline axels adn i have gone 12's on them with slicks and 3.55 gears, but i jsut got new gears (4.10) but i have not ran them with slicks yet, so im hoping they wont break.

Look for an 8.8 out of a truck, they fit 31 spline axles. The ford 8.8 is very strong IMO. The 28 spline axles and c-clips are the weak links, upgrade them. The ford 9 inch is overkill, lots of cash and weight, but they do allow easy gear swaps. I have made 1.79 sixty foot passes on drag slicks with stock 95 8.8 rearend with 3.73 gears. I have beaten my 8.8 with NO MERCY and it makes sounds sometimes, but then I just make a few drag launches and it seems to help... no... seriously, I don't know why but it gets quieter. I will run it till it breaks, then put another one in, I know a guy that runs 9's on an 8.8 rear(upgraded tho) and he says he'll use nothing else till he finds the limits.

Doing a 9 inch is stupid. It takes approx. 60 horses to run a 9, plus they weigh a ton and cost like 2 grand. There is nothing wrong with the 8.8. Hell, I'm pushing 516 at the wheels with a 31 spline 8.8. I originally was running my 7.5 with 28 splines when I was running in the mid 13s. The 7.5 isnt as weak as everyone makes it out to be. How much power do you plan on running. A cheap and easy mod is to source an 8.8 and use a truck 31 spline posi unit. Then just get some aftermarket 31 spline axles. You can do new gears, axles, carrier, housing, parts and labor for less than $750 or take 200 off if you do it yourself. Or score a T-bird 8.8 with posi, 3.73s and disc brakes. Its all up to you, but I say an 8.8 with 28s is going to run just fine for your car.

I have witnessed 2 8.8s that had nothing more than gears and one an Auburn posi unit.

First one was/is a Capri RS that ran multiple low 11 second passes and a fair bit of 60's in the 1.50s and 1.60s. It's a Renegade car now but still uses a built 8.8.

The other is a buddies 89 LX. Rear was stock with 3.73 gears and thats it. Even higher mileage.. has about 5 low 11 second passes so far and 2 high 10s bwest being a 10.77 @ 129 MPH and the 60 was a 1.68..

I'm sure the above 2 are pushing it, but they are both fast stick shift [shocks the rear harder I think] stock 8.8 cars.

Had a buddy with a Convertible 85 GT that had a 7.5" in it with 3.55s and he beat the car until the cows came home and the rear held up. He rode around constantly on Hoosier Dirt Bozz stickies, and street raced every weekend and then some.. many many 4000 RPM clutch dumps & it was a high 13 second car.. It took the beatings.

PS - why is it that almost every 8.8 I have seen will almost alwyas at one time or another get the infamous 1 wheel peel, whereas a 7.5 [in a GT or RS or whatever] gets 2 lines no matter what? [ones i've owned and the 7.5s i've seen]

Upgrade to the 31 spline axles.I broke two 28 spline axles in my 85 G.T. The car runs 12.50's in the 1/4 on ET. Streets. I snapped them off on the drivers side right at the end of the splines. Luckily this happened on the starting line and not going 110 M.P.H. down the track. The first one had too many passes on it to count. The 2nd one only had about 6 passes on it when that one broke. From a safety standpoint you should change them. It is not worth the aggrevation to keep swapping the stock 28 spline stockers when they break!