I've spent a ton of money on a lot of 8 3/4 trying to make them live with sticky tires, a TON
The manual trans will break the driver side carrier cap which will kill the other parts, I've seen a bunch of 8 3/4 ring gears with the outer side of the teeth cracked with motors making less than 500 HP with slicks at the drag strip, I had one tooth corner break off and go through the pinion and ring gear, tore that rear end up.
As far as you building or buying a complete rear end do you have a shop that can narrow a housing that you trust? If so junk yard Dana 60 pickup and van read ends may be a good option for you, some of the Ford F150 pickups from the mid 1980 to mid 1990 came with a Dana 60 with conventional 5 lug wheels and brakes so if you could find one of those it would be a good choice to narrow and reuse in your car.
One thing you need to know is Dana Corp made a bunch of different Dana 60 for the cars, vans and pickup, the axle tubes can be from 2.5 O.D. to 3.1/4 O.D. so be choosy on what you buy so it will work well with your U bolts and spring retainer plates
Dana 60 never came with a 3.90 gear, 3.54, 3.73, 4.10 and up to 5.57 stock, maybe even 6.17 in some of the Air Force 3/4 ton four door Dodge crew cab flight line 6 cylinder pick ups
Dana 60 came with 17, 23, 30 and 35 spine axles stock also.
IHTHs