Will a 4x4 rear complete rear end bolt up to my C1500 2wd 95 chevy truck? I know it is wider, i know it is 6 bolt compared to my 5.
Will it bolt up without modification.
WHICH rear axle do you have in the C1500, and WHICH "4X4" axle do you want to put in?
2WD 10-bolt-to-4WD 10-bolt should work. I think the spring spacing, and shock-absorber mounts are in the same place. I'm NOT positive, and I have NOT done this swap. Frankly, that's a lot of work to get another crappy 10-bolt axle with crappy 254mm leading/trailing brakes.
10-bolt-to-14-bolt semi-float should work, but you'll need a conversion U-joint on the driveshaft, and the larger, 14-bolt semi-float U-bolt brackets from the donor vehicle. Again, NOT positive on spring spacing and shock-mounting. At least you'd have a MUCH stronger axle with far better 11.x Duo-Servo rear brakes.
The 14-bolt Full-Float axle is probably going to need a shortened driveshaft AND a conversion U-joint. Very overkill in a half-ton truck. Gigantic 13" brakes of either 2.5" or 3.5" width.
Not recommended.
VERIFY SPRING SPACING AND SHOCK MOUNTING. And you'll need new U-bolts no matter what. The two rear park-brake cables will need to be for the truck you have, which may be different from the donor vehicle, depending on cab and box length. If yours are good, re-use 'em. Otherwise you'll need new ones--which is pretty typical.
Also common to have to replace the two sections of brake tubing from the axle-end of the rear brake hose, out to each wheel cylinder, due to rust. Of course, you'll be inspecting/repairing the rear brakes as needed.