8.2"
85-140 will work.
Depends on the rear axle the car has. 10 bolt is most likely 8.25" for a 1968, but 8'5" is also possible. 12 Bolt is 8.875".
It should be an 8.2 10 bolt unless it was changed.
Removing a Nuetral Safety switch on a chevelle is actually quite easy. You take out four bolts and remove the gear shifter and then remove three more screws and unplug a pigtail and the safety switch comes right off.
All depends on the engine in it and the rear gear ratio.
Depends on engine and rear gear ratio.
While the axle code is stamped on the passenger side axle tube, the most reliable way is to take off the back cover and count the teeth on the pinion and ring gear and divide the numbers because there is NO guarantee the gears are original.
These cars came with a 10 bolt, 8.5" ring gear and an optional 12 bolt 8.875" ring gear.
that all depends on what engines your talking about and rear end gear ratios but basically the chevelle SS 396 would whip a cougar eliminator.
all depends on your engine and running gear and if it's a #'s matching car.
If it starts in ANY gear, the neutral safety switch has most likely been bypassed.
10 bolt or 12 bolt has NOTHING to do with gas mileage. It is the gear ratio that is inside of the rear end housing that affects the mileage. The lower the gear the lower the fuel mileage is. The higher the gear, better the fuel mileage is.