Will a 1992 caprice rear end fit a1978 caprice?

Answer 1

not really. First, the wheel bolt pattern is different. The 92 has a 5x5" bolt pattern. The 78 sedans and coupes have a 5x4.75" pattern. Also, the 92 has an ABS sensor in the snout of the center section (this isn't a deal breaker, but can't be taken out). The biggest problem is that while the rears look simillar, the trail arm angles and placement and the actual width of the rear are not exactly the same on the two years. Your better bet is to find a rear out of any 77-90 GM B-body. All of them will fit. The only exception is that all wagons and all Cadillacs and Buicks are big bolt pattern (5x5"). Olds may also be big bolt.

GM B-bodies include Chevy Caprice and Impala, Pontiac Parisienne and full size Bonneville, Buick Electra, Oldsmobile Delta 98, Cadillac Fleetwood.

If it is gear ratio that you are concerned about, remember that 3.08 and numerically lower use a different size carrier than the 3.23 and numerically higher. If your rear is good and you just want a better gear ratio, I would recommend getting a new carrier and ring and pinion. The whole thing shouldn't be much more than about $600. The 78 should have a 2.76 rear if it came out with a 305 engine. If I were you, I'd just keep the rear you have and put a 3.08 gear set in it. That will give you plenty of extra torque but still yield good mileage.