7.5 inch rear worthless?

[350GST]

Do you guys think the stock rear in my Regal would withstand 400hp on street tires? I'm thinkin the spiders are the weak link, so if I replaced the diff, it should be OK. Getting rid of the Bonneville gearing will help in the accel department, too! Thanx, Jay

[SS-TRUCK]

Its not just the carrier thats weak . The whole unit is small and that has problems holding the power . The axle tubes where they go into the center housing need to be welded solid and a rear cover girdle needs to be installed along with strut rods running from the rear cover to the axle tube ends to help reduce flex . I know this because my son has one that we have worked on several times due to his heavy right foot .

[KRL077]

Maybe this will help:

http://www.v8buick.com/showthread.php?t=149321

[monkeyy337]

If you don't get to crazy on the rear gear it may last for awhile. If it were me I would not go lower than a 3.42 gear.

[SS-TRUCK]

Since the above mentioned mods we did on our rear housing we have not broken it yet . We are using 3,73 gears .

[RKHiPerformance]

We shattered (really shattered!) the spider gears in a 3.42 7.5 with just a part-throttle launch on drag radials.
I would not suggest spending any money on the 7.5. And if you break one of those spindly 7.5 axle shafts, it could be disastrous for the quarter panel and also very dangerous.
Get a used 8.5" posi assembly and upgrade it as funds allow. :TU:
These guys sell 8.5" rear axles all the time:
www.gbodyparts.com

HTH,
Rick