Hey guys, just realized that I have a 2.56 ration one-legger on my 71 Skylark. Is it possible to use the existing carrier and upgrade to 3.08 or 3.23, or do I need a whole new set-up?? Jay
You can upgrade however far you can afford to go, however checkout this thread. :bglasses: http://www.v8buick.com/showthread.php?t=104246&goto=newpost
Okay, thanks for the thread! Now if I stay with the 2.56's, how do I make it a posi unit?? Is that possible, if so how??
See I heard that if you have a 2.56, that as high numerically you can go with that carrier, but if you have 2.73, then you can go all the way up?
2.73 is a 3 series carrier requiring a 3 series posi unit, 2.56 is a 2 series requiring a 2 series posi unit. I had to find one by advertizing in the parts wanted section of this board. Guess I should have asked what engine your running, if your running a SBB you'll need more gear than a BBB would.
You can fit any gearset to the 2.56 carrier, you do need to use a spacer though. I recently fit 4.10s to my 2.56 carrier. I was lucky, mine was a posi unit. The idea of a 2.56 posi still boggles the mind....why? Your project starts getting spendy now. Finding a 8.5 posi unit shouldn't be too hard though. Drop down a couple threads and read through the one I started about doing the job at home. There was some mention of the posi units in trucks that will work but might not be a great choice. Aftermarket units are $400. Chances are, what you will get in a used deal will be a 2.73 and up carrier that doesn't need the spacer. Either one will work in your rear end housing. Also note that if you use the 2.56 carrier and deeper gears, make sure you get the reverse thread split lock washers before you start the job. Regular ones do not work for beans. There is part # info on the other thread for these too. As far as ratios, I really like the 3.42s in my GS. Muffler choice has a lot to do with this. My wifes Nova with 4.10s and flowmasters is cool sounding till you have to drive it 30 miles at a crack. Then it is a little too much. I have long case Walkers, and the car runs ~2800 rpm at 60-65 very quietly. I could drive it all day. It is enough gear that the BBB will burn the tires at will :3gears:
Eaton Posi carriers are a good bet if you want an upgrade that is strong, Easy to find. Randy's ring and Pinion has best price I found. Better than using used original. Most rebuiders don't like using used ring and pinions as well and some won't guarantee them.
posi posi posi You can use a spacer just get the proper bolts and sometimes needed washers. Should have no problem with it. You can still find used posis in the yards 2 -3 series...I also have them. I do not sell used I sell reconditioned and checked out. That is as cheap as I will get. I do not want to sell anyone that has to go though all the work of a gear install to get a piece of junk. It will work from me. If you need new or used gears I have them and also the eaton posis auburn units factory reconditioned etc. just email me for prices on the posi...Oh and I will bet Randy's price. lol. Jim J D Have a great weekend of hot rodding
D Berry, it is a freshly rebuilt 350sbb, with a compcam 260H, increased compression, th350 tranny with a shift improver kit, and a saturday night special TCI tourque converter with flowmasters. I feel the engine can make a lot more power, but if I punch it off the line, the pass rear tire just spins loose, every time, or a start a slower start, but it's a dog until spped gets up. Now on the highway, it great, but I'd like a small compromise, I think 3.08 would give me the best of both worlds. Jay
In your case I'd say 3.08s is probably the best choise, I have a 462 with tons of bottom end and get by just fine with the 2.56s. Colorado GS, in my case the why is several things, increased gas milage, lower noise level, engine runs 10 degrees cooler, and the look on peoples faces when they ask what gear I'm running. The car doesn't feel nearly as good out of the hole as it did, but the gear change only cost me four hundredths of a second in my quarter mile ET. Just pulls harder on the top end. Even though the car doesn't feel as good that 4 hundredths is all in the 60 foot times.
I'm with Dave on this one, always have been. If you don't ever plan on seriously racing and you have a 455 (even a stock one) Numerically low gears is the way to go. 2.56, 2.73, and the 2.93's I have are really nice. I don't think I'd ever consider going above 3.23.
I have a 72 455 it had 2:56---I upgraded to a posi unit with 3:42---which is cool :laugh: UNTIL you are on the HWY @ 70 mph/3000RPM :af: ---I beleive 308 is the WAY to go but I aint spending money to change it NOW, also since I got my tranny governor shifting right on 5000RPM---thats 1-2@ 48mph and 2-3 @ 80 mph PERFECT :bglasses: See what hapeens when you TAKE OFF :eek2: :eek2:
