I'm debating weather to get a 9" rear end, or a 12 bolt. I plan on putting down about 600-700 rwhp with a 383 and a GMR Speed front mount Turbo setup.

What I wanted to know is has anyone ever broke a 9" rear? I have seen, and read about people breaking 12 bolts, but never a 9". I just wanted to verify that a 9" is stronger. If you have broke a 9", what happened to it?

Thanks

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1994 Pontiac Formula
M6, CAI, Pro 5.0, 18" C6R Rims
*383ci Front Mount Turbo Build In Progress*

 

9 inches are beasts. I have a friend with a BBC 69 Camaro that runs 8's at 160mph. He has a 9inch in it, and up until a year ago he was running a stock cast iron case. He was showing off and turned up his nitrous off the line and busted the center section housing in 2. He just now finally upgraded to the N case cast iron housing and is doing great on that.

 

get it built like mine and you will never have a problem, spend the extra money and the the moser center that peice is masive look at the caps on that thing comparted to a regular case

 

Just a question on that new rear you have there. exactly how do you change the fluid / gears in it. it looks to have the area where the stock pan is welded on and over...

 

ford 9s you set the gears and everything up in the third member and then it bolts to the front of the rear housing, theres a fill plug in the front, I drilled and welded in a drain plug in the bottom of mine, thats one other + to a ford, you can have as many sets of gears set ap and ready to bolt in and you dont have to set them up every time like a standard rear.

 

ahh it makes more sense now why they are stronger then. Has anyone here seen a 14 bolt GM rear? I know you can buy ring and pinion sets for them. and they are a little bit bigger than a 9". just never seen one..

 

Yes, you can find them on heavy duty GM trucks. They come in 9.5" and 10.5" ring gear sizes.

 

I had just got done doing three lapping sessions at Hockenheim ring. I pulled off the track loaded to go home . Everything normal and all and KABOOM,the nine inch dropout cracks. It must of been a defective case . Glad it broke doing 20mph and not 140mph .

 

I've never broken one myself, seen one broken on a buddies 67 Chevy P/U with a 406 on nitrous. He had trouble with a couple of the third members but thats the only problem I can remember. He got a 9" race case from someone like Strange or Moser I believe and hasn't had any trouble since. That setup put roughly 800hp at the wheels on the bottle, so they're fairly durable.

 

AND 11.5"