Quote:
Originally Posted by ponyakr
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We have one vehicle here we've run C-clip eliminators in the 12 bolt for about 15 years now, no leaks. Primarily street driven with maybe 2-3 track outings a year. We settled on Strange C-clip eliminator and axle setup. First Moser was tried and it leaked almost immediately. Never a problem since the switch to Strange.
I'm much like you with rearends. I've run basically stock chevy 12 bolts with excellent success with very heavy 4,000 lbs. cars that have run close to the 10 second barrier. One in particular the 12 bolt doesn't have anything more than a Moroso Brute strength posi, and a set of non taper heavy duty Moser 30 spline axles that still use C-clips. No fancy welded axle tubes, no stud girdle support brace cover or any of that stuff. I built that rear back in 1988, countless drag strip passes, 4100 lbs. race weight, 1.5 60 foot times, and at least 30,000 street miles. I never have to touch it.
My father is still running a chevy 12 bolt in his 69 goat. We built that with Strange C-clip eliminator axles setup, still 30 spline, and rebuilt the original GM posi unit with a little more preload on the clutches. That's it. Nothing fancy, no stud girdle, no extra welding anywhere. It's been in the car like that for about 20 years. It's had 4 different incarnations of 455's in front of it and pulls nice wheelies with 1.5 short times. It's a heavy 3900 lbs. car as well and has seen tons of track time. Now he has a 571 in front of it making 760 ft lbs. of torque. I'll admit he is a little sketchy of the rear now but I'm a little more relaxed about it. (I worry more about the stock driveshaft) It hooks extremely well on the street (that car always worked good no matter the surface) and several hits with it now he is getting a little more comfortable with it. Eventually a 9" is going in the car with a better driveshaft and 1350 joints, but I really don't sweat a stock 12 bolt with an axle upgrade, (too much
) Given this power level now it has me thinking about it, lol.
These cars with automatics in them are really pretty easy on parts, and that's what these examples are that I'm giving. Unless you're running a transbrake I don't worry too much. These cars also are still running their original bone stock driveshafts too, and I would suspect they will break long before any of those 12 bolts give up. I worry more about the driveshafts than anything else, but they keep going (I run good joints and driveshaft loops of course)
It's the stick cars you really have to pay more attention to. On my stick cars here I tend to go a little more overboard with rearend and driveshaft requirements if I plan to hammer the car at the track at all.
My opinion, in a street driven car that might see the track 1 or 2 times a year with an automatic behind it, a basically stock GM 12 bolt, maybe an axle upgrade, and that's all you need. You don't have to spend a ton of money. A setup like that has been reliable for me to bottom 11's in 4,000 lbs. cars. Lighten the car up, say a 1st or 2nd gen firebird, and the stress becomes much less, hence even easier on parts. Just my experiences.