71 88 royal differential

[seasand77]

Can the differential be rebuilt? Are there places that sell rebuilt "Chunks? Is it an expensive rebuild?

Also, The engine is an F block with G heads and a two barrel 455 ci. I guess this was a stock set-up. Can the heads be changed easily when I decide to up date to a four barrel?

[rocketraider]

First thing you've got to do is determine which differential you have. A two-barrel big car used the same 8-1/2" 10 bolt rear end gearset as a Cutlass and those are easy to find and set up. <span style="font-weight: bold">UNLESS...</span> the car has heavy duty rear brakes or anti-spin differential, in which case it will have the 9-3/8" 12 bolt rear end. (Don't ask why they did it. I don't know <img src="http://www.aaca.org/ubbthreads/images/graemlins/confused.gif" alt="" />.)Your gear ratios will be limited with the 9-3/8" punkin. 3.42 are the highest I know of and they're not common- some big Cruiser wagons had them (and also leaf springs, so the rear axle is not a bolt in swap) or you can look under a 71-76 Riviera GS which had them. Most are gonna be 2.73 or 2.93, sometimes a 3.08.

G heads will work fine with a four-barrel intake. Yours will have 2.00" intake valves and 1.62" exhausts. You can install 2.07" intakes if you want. Olds changed compression ratio with the pistons not the heads so you won't get any benefit changing to a B C or E.

[seasand77]

I ended up getting a 71 Impala rear end from a junk yard. It was in very good shape and bolted right in. Thanks