Which rear end to use?

I have a complete 8-1/4 rear with large bolt patteren peg leg with high gears that cam out of an 65 plymouth barracuda.i was planning on having it rebuilt / modified posi with 3:55. I found an 8-3/4 rear out of 1967 coronet thats missing the guts and axle shafts. Which is cheaper to fix up? I know the 8-3/4 is stronger but? I'm dropping in a modified 360 under 400 hp with full manual valvebody 727 automatic . The cars unbody and suspension will be beefed up . Its my 65 dart I'm working on. Thanks for any help you guys can give me