Thanks to some information posted on this board, I found an 8" rear end at the junkyard with 3.40 open diff gears off of a 75 Bobcat wagon. I couldn't get just the pumpkin off so I had to get the whole rear end for $59 (+core&tax). The door code indicated that it should have 3.55 gears, but they were only 3.40. My question is: I plan on swapping out the 2.79 gears in my Mav for the 3.40's. The car will be mainly used for cruising on the street but occasional at the strip. How high will the car be revving when cruising down the highway at 60mph or so? The car has a stock 3 speed manual trans and I'm thinking the gears may be a good compromise for quickness yet still streetable but don't want to blow up the engine driving on the freeway. What do you guys think? Thanks. -Erick
I am only guessing, but I would say your RPM's at cruising speed should be about 5-700 higher. Wide range, but it's just a guess. Seth
Great info...looks like 3.40's will add 400 to 500 RPM, and a total cruising RPM of 3000 or less. Sounds tolerable. Thanks.
Good find. I think you'll really like them. Let us know! Dave Throw your highway chunk back in the rear and get your core charge back!
I don't think bobcats have 8" differentials, do they. Isn't it Mercury's version of a pinto? That is a 7.5?
No, it was a V-6. It had some pretty cool blue rims w/ beauty rings too. I wonder if the Pinto guys would need them.
I went to randys ring and pinion (I think it's differentials.com) and was playing with their calculator. It has auto, aod, manual, and 5spd and it figures them all at once. Check it out.:bananaman I love the dancin nanner.
ok...so one more possibly stupid question.... will the rear be a direct fit for my driveshaft? thanks
