12-bolt question

**Ric** · 09-11-2005, 07:18 PM

I'm looking at a rear end swap in the future, not so much to handle tons of power(yet), but more for reliability. I'm still leaning toward the 9" getup due to the press-fit bearings and other goodies, but can someone tell me the safe power limit of a 12-bolt behind a T56? Thank ye... uhh, thank ye vury muuuch.

**Zboner** · 09-11-2005, 07:21 PM

Originally Posted by Ric

I'm looking at a rear end swap in the future, not so much to handle tons of power(yet), but more for reliability. I'm still leaning toward the 9" getup due to the press-fit bearings and other goodies, but can someone tell me the safe power limit of a 12-bolt behind a T56? Thank ye... uhh, thank ye vury muuuch.

a shit load 500hp maybe more, i have a 70 Chevelle with a 4 speed muncie and a 12 bolt rearend, i dump it at 4,500rpm's and i never think twice about it. i have never had any problems with it at all. but the Chevelle has about 350hp at most.

**Exotic Performance Plus** · 09-12-2005, 03:34 AM

We install a lot of Moser 12 bolt rearends behind boosted engines that give us 450 to 700 rwhp, and we have not had any problems yet. Bob

**J&J Speed Shop** · 09-16-2005, 08:46 AM

Originally Posted by Ric

I'm looking at a rear end swap in the future, not so much to handle tons of power(yet), but more for reliability. I'm still leaning toward the 9" getup due to the press-fit bearings and other goodies, but can someone tell me the safe power limit of a 12-bolt behind a T56? Thank ye... uhh, thank ye vury muuuch.

Well unless you really need the easy change center section capability of the Ford 9" then I would suggest the 12 bolt. They are a bit cheaper, take less HP to turn because of the pinion angle, and are ultra durable. I have a customer that I just built a complete engine/combo for. He is making over 700 hp, through the T56 and a Moser 12 bolt

bottlefed · 09-17-2005, 05:00 AM

12 bolt sounds better

**Hurley711** · 09-17-2005, 07:26 AM

Thought the rule of thumb was 12 bolt for A4, 9 inch for M6....or is that just plain bullshit?

**J&J Speed Shop** · 09-19-2005, 10:16 PM

Originally Posted by Hurley711

Thought the rule of thumb was 12 bolt for A4, 9 inch for M6....or is that just plain bullshit?

That is plain BS as far as I am concerned. I have many high HP customers running a Moser 12 bolt with T56 trannys. The only reason I would recommend a 9" to someone over a 12 bolt would be a full blown very high HP drag car, or someone who wanted the fast center section (gear) interchangability.

**Z95SSCLONE** · 09-20-2005, 12:00 PM

go strange 12 bolt!!!

**bww3588** · 09-21-2005, 06:38 AM

will the mosier or strange 12 hold up under a launch at the strip with tall stickies?

**J&J Speed Shop** · 09-21-2005, 07:59 PM

Originally Posted by bww3588

will the mosier or strange 12 hold up under a launch at the strip with tall stickies?

Both will hold, IMO the Moser is a heavier duty unit at the time I was evaluating both and seeing which one I wanted to sell and install. If you are thinking lots of drag lauches I would looking into the Detroit TrueTrac diff if you want a posi, all worm gear and no clutches to wear out