Help, want a posi for the x body, and most tell me no 7.5 or 10bolts, as the 455 will chew it up. See I have a 455 with a mild cam and good exhaust and cant keep the car from breaking out at 45 mph due to one wheel. As always most say use ford 9 or plymouth 8.75 cut to fit. what are the cost and would a big car Electra cut to fit and mounts work better, (have an electra posi)? Have a camaro posi with 3.08 posi and it is the latter 70s numbers , but will this fit with new spring mounts or is it too wide? and will the camaro stand to 455 buick torque on the rear? Have a 3.5 Electra drive shaft built to fit so feel this is safe. What about trannys, some say 350th have better 1st gear launch than 400 or 375. I have a 375 with b and m shift kit already in but the tranny is 3 inch longer than the 350 and have cross member problems with that. The Exhaust is a 2.5 mandrel bend pipe set and breathes good. Any body mods needed 455ers? Want to GS Nats maybe this year, help me with advice please, craig at c_geske@earthlink.net BCA #27925 Minneapolis :3gears:
Just an idea! I would suggest the 76-79 Cadillac Sevilles. Those are 8.5" rears and have disc brakes. You can get a posi from any GM 8.5" rear from 71-89 car/truck/van. Measure your rear and see if the Seville rear will work.
Had a 74 Apollo about 10 yrs. ago. Ran a .030 over 455 Pontiac / TH350 & 3.08 posi. Used a donor Ventura to set it all up. The trans & 8.5 10 bolt held up well, even at the drag strip. The "X" body is lighter than the "A" body. So your factory 8.5 diff. should be just fine. Just add posi & have fun :3gears:
I agree with speed70. The original 8.5 rear that your Apollo came with from the factory is pretty tuff. Put a posi carrier in it and I bet you wont have any problems out of it. If you are running drag slicks and doing alot of racing with it and feel safer with a 12 bolt, find a rear from a 68-74 Nova or a 67-69 Camaro or Firebird. They will bolt right in without any Mods. If you want a Turbo 400 behind the 455 and worried about the 1st gear ratio, you can install a lower ratio 1st gear in it.
