if its an 8" ya might be able to change out axles and backing plates,, at the worrst case,,, change out the carrier assembly and leave the case still in the car
you have to change out the case when going to 5lug. the bearings and the bearing housings in the case are smaller and wont swap out. just pick up a 5 lug rear, swap the whole thing and have better/bigger brakes and 5 lug all at the same time...
here is the deal my rear end was 4 lug i drilled out the axels and the drums and i have had no problem with it went to 5 on 4.5.....so any machine shop can do your axels and if you dont wont to drill out the drums you may get new ones if you dont wont to drill drums.....
well if u drill the axles then chances are you're going to HAVE to drill out the drums as well because if u just go buy 5 lug drum, they're going to be for the bigger grakes versus the smaller brakes that you would be running.... just my thoughts
...i drilled both of mine so they would match..... then bought a parts car to get the ...front disc. swap stuff...and put the ...5 lug rear end...in also... looking back...the drilling to me was not worth all i went through to get it done...JMO ......
but im doing a budget build because im a poor man with a hobby (i no poor and hobby dont go together but what the hell) ha ha ......and buy a parts car im doing good to have one car nevertheless two of them ............
to be honest i work in a tool grinding shop for special tooling i dont do the pricing and am not sure what they would charge. I run the machine shop but dont price the stuff but if i were doing this on the side 40.00 for both axels and drums drilling them out... of course he would supple new studs to press in.....
..."on the side $40"... ...welding up and finish out...2 axels ...welding up and finish out...2 drums ...drill 2 axels ...drill 2 drums ...press in 10 studs ...through the shop price...$XXX ...plus 10 new studs.........$XXX ... 2 new tube seals.........$XXX total $ too much ...again...JMO ...:Handshake...