You will more than likely be fine with just changing the ring gear side cap, that one sees the highest loading. An engine shop can fit the cap, take the empty case with the cap installed to the shop , they can measure the hole size , swap on the new cap and see how much larger the hole is and cut the cap to bring it back to spec.

I vaguely remember having to take close to .125 off the one I had done, the shop did the major cut in a bridgeport and used a rod cap grinder to finish the job .