Axle ID and disc brake question

[55metalmonkey]

I was wondering if anyone can give me an idea on the rough year this axle is ? it came with the truck I bought and don't have a clue for the year. The previous owner had it overhauled and put quite a few bucks into it but I haven't cracked the case yet to find out the gearing

I know it's a chev 10 bolt with a casting #1254333 likely from a 2nd gen f body or S-10, but I think the disc brakes are an add on from the previous owners build... this will be going into a lowered 55 GMC with a camaro front clip BTW
the main reason I'm asking is that I'm pretty sure the location and style of the parking brake cable is going to have a clearance problem with the rims I was looking at 17-18" and the tire width/ back spacing.

I'm curious if I can change the disc brake setup for a style with the internal drum for parking and outer disc for the brakes without running into 5 other changes that have to go along with it. also the one brake fwd and one rear doesnt appeal to me either, I'd rather have them top rear

any sugestions or experience with this type of swap without buying a $800 kit, I'd like to stay with off the shelf chevy parts