Maybe someone with more knowledge than I have on the 8.2 can answer this for me. I know that Olds went to a funky 12 bolt set up but didn't the 68-70 Pontiacs use the same ring and pinion as the Buicks did? If so then we should be posting this pre-order info over at the Perfromance Years website.
Anyone else here for a 3:08? I've heard its a very popular ratio and with gas prices going to the moon it would make crusing more affordable and some less wear and tear on the motor. For people with sub 3 ratios (most peglegs), it would still be a quicker result! Sorry to muddy the water.... - Bill
Thanks David, is there an equation you use to find out the numbers? I also want to know what would be my mph at 4000rpm and 5000rpm. I'm trying to figure out if i'll really like the 3.42 so I can be part of the pre-order group for the new 3.42s since its really hard to find some used 3.23s. Also if I change from 2.56 to 3.42, can I change the speedo gear with out removing the transmission? Do I also have to change my ac pully? Anything else I have to change? Thanks Shawn
The pinion is at a different angle on the Pontiacs. Also the Buicks have 7/16 threads to the Pontiacs 3/8.
Sure doesn't feel like it! Course that could be the 110k mile motor too. ou: Well, I am still interested in knowing what it would cost to convert it over to a 3.42 posi. I have new Gardner exhaust coming, and Rick rebuilt the front end and put front and rear sway bars on it and front disc brakes, so now I need some gearing!:TU:
15 sets to go. C'mon guys. We need to make this happen. Think about how much it will cost to buy that 8.5 and have your driveshaft shortened. This will be cheaper.:beers2:
Money to convert to 3.42 from 2.56.... Well unfortunely the 2.56 is it's own carrier. It is the lowest acrrier and can only be spacered up to 2.78 and 2.93 ratio at the most. if you had a 2.78 2.93 carrier you could use a spacer to use the 3.42 gears. So a whole carrier for you will have to be purchased which after 35+ years might be needed anyway...lol. for you guys 379.00 for the Auburn posi prepped for the ring gear That means redrilling the ring gear bolt holes to 7/16" properly. I can installthe correct bearings for your housing for 45.00. then the cost of your 3.42 gears of course. so 379.00+45.00+ 405.00=829.00 sounds like alot but these days that is what any rear cost to build with very minimal quality parts. I sell 8.2 rear wit all new stuff to the pontiac guys for just over 1000.00 pontiac aftermarket gears are up to 274.00 now. Nothing is getting cheaper. I think this is got to be a team effort. Jim
Jim, is that the same if I have 2.93's already? Also, would it make sense to have the gears just shipped directly to you for assembly? Thanks, Chris
Jim, thanks for spelling it out for me. I've drained/cleaned/refilled the rear, but that's about the extent of my knowledge and experience. Will have to think about this a bit. While the upgrade would be nice, it's not very high on my spending priority list, and may not be in the budget with all the other vehicle maintenance projects I've got to do this year with both cars. I'll update on the interest thread.
I need some help on that decision also. I found (laying in a scrap pile) a 2.93 stamped posi buick 69 wagon.Years ago. I grabbed it freebee. What do I need as far as a shim goes to convert up to 3.42? This would be great if I had a def answer and new that I wouldnt be ordering an anchor. The car now has a 273 set one legger and will be converted to 4 wheel disk. I would so like to do the rears before I slide it under and cut my driveline to install the newer 4l80e tranny. Please PM me the answer so I dont take up anymore board posts. Troy
I am ready to commit to the 3.42 gear pre order. I just need a little help with a some detail info. For my car (350 factory high compression, th350, 2.56 pegleg 8.2), to change over to 3.42 gears, Do I just need a posi unit and speedo gear? Or do I also need a pully for the AC? I just want to clearify what I exactly need before I commit. Is there anything else needed to change over? Do 3.42 gears cause more wear and tear on my engine on the freeway? I drive a lot on the freeway. Does anyone know how fast I will go at 4000rpm? Thanks to the guys who started this project. Thanks Shawn
3.42 is not a good freeway gear ratio. Yes it will put more stress on an engine. In general for these to fit you would need another carrier. How fast you will go at 4000 rpm requires knowing the rear tire size to be used.
My tires are 225/70/14 now but will soon be 245/60/15. 3.42s are bad because you cruise at a higher rpm? If I just drive slower on the freeway it will be better right? Thanks
Someone will do the math on the 15inch but Dads stage 1 does screaming rpms it seems with a th400 and 342 at 75mph. Im converting to a 4l80e overdrive tranny to improve fuel economy to the point that alternative fuel will have nothing on me. There is a guy that put this tranny into a homemade GNX and gets 35mpg with a diesel engine. 18 to 1 dot com and you can see it too.... Anyway anyone know if I can shim this 293 for the 342?
You can shim the 3.42 to fit the 2.93 carrier. I guess if I drove 75mph on the freeway I wouldn't want a 3.42 either. A high 2. would be better for that but I'm not sure how much freeway time a lot of these cars see anyway. 3.42 is still a very good all around gear.
