I have my skylark set up with a 455, TH350, 2.56 gears. and 29" tall tires. I love this combo, the 455 has plenty of torque to turn the 2.56 gears, and I can cruise at 75+ MPH all day on the interstate with no problems. The one downside with this setup, is that the open diff doesn't work out so well on anything other than dry pavement. I do occasionally end up in situations where I wish I still had a posi rear in the car. Sometimes I do leave the paved road with my car, and dirt, wet grass, etc can make maneuvering difficult at best. I have found, though, that there are virtually no options available to keep the 2.56 gears and add a posi. The only option I've seen is the lock-right or the no-slip units from Powertrax. I haven't had any luck finding a 2 series posi carrier. I do have a 8.5" 10 bolt with 3.08 gears on hand as well, but I really don't want to increase my highway RPMs. I've been down the 700-R4/200-4R road already, and I don't have any desire to go back. With both of those trans, I ended up with driveline vibrations, and all the trans mount shimming and driveshaft balancing I could do wouldn't totally eliminate it. My current setup is smoooooth as silk running down the road and I don't want to screw that up. Thanks!
I know how you feel about the 2.56 drivability. Smooth like floating on a cloud. Makes driving a true pleasure. I had a 67 skylark and I installed a 68 O-type Olds 2.56 posi rear, and oh how I miss that car. If a lock-right fits your carrier, I'd look into that. Check with others to see if the ratchet action is a nuisance or not. Also, the "LOCK" feature may make rain driving a little slippery.
That is my main concern, I don't want to have something that makes noises or jerks/bucks arouond turns, or causes the back end of the car to want to step out when going around a corner in the rain. I wish there was a Torsen style diff for 2 series carriers.... My '02 TA (RIP) had a torsen... Loved that thing.
The very best choice for street/strip, rain or snow, is Detroit Truetrac with worm gears. In my humble opinion, it is the ultimate choice. No downsides. Smooth as silk, tough as a forged steel sledgehammer. Ask Monzaz, on this site about 2 series application. He has good used stuff at his place too. ---------- Post added at 10:35 PM ---------- Previous post was at 09:40 PM ---------- Did some searching. Truetrac fit up to 2.73. Could not find 2.56. Monzaz may have a 2.73 laying around for cheap. May save you money on Truetrac too.
Maybe this will work ??? http://www.ebay.com/itm/Posi-GM-Che...Parts_Accessories&hash=item257e8434cf&vxp=mtr
I'm happy with my Lock Rite.. You can install it yourself, and take it back out your self if you don't like it. It's easy.. It does lock under power though. So, if you are trying to back up a hill on grass and turn at the same time, you will pull some grass up. But you won't sitnspin...If you take a right from a light and are heavy on the throttle, it wil chirp the inside tire. Been running it for 5 years, would use it again.
dont think there is a posi that accepts 2.56 gears, as posted above, 2.73 I also think tru-trac is the best street unit for a 10 bolt...unless wavetrac actually releases one for 8.5..till then 12bolt and ford 9 only :-(
Oh nice, they did make 'em from the factory.... $199 for a used posi seems kinda steep tho... Maybe if it doesn't sell, I can haggle with the seller LOL. Thanks for the link, Ryan! Jay - how many miles would you say you've put on the lock-rite in those 5 years? I was somewhat concerned about the longevity of those units, with the teeth engaging and disengaging alot. Does it make any noise in normal (non aggressive) daily driving? Ratcheting, clicking, etc? Thanks!
I honestly don't know how many miles. Like both of my Buicks it rarely gets driven 3-4K maybe??.. It only makes noise when you make a sharp turn at slow speeds. Like a U turn, or turning into a parking space.. I see no reason why it wouldn't last longer than you would ever need. At least it something you can install and remove with no special tools or knowledge. I'll send you the install guide if you give me your e-mail.. The ratcheting noise is really no big deal to me..
