Rear end Swap...87 1/2 ton

[454c20]

Hey guys. I just picked up a new project, its an 87 4wd 1/2 ton. Overall its very clean. New doors, new front fenders, grill and trim, bed is very solid, just need to weld on lower patch panels and one wheel arch. Frame is great. Does need rockers (inner and outter) and cab corners but the cab supports and mounts are awesome. I was very pleased with that.

I had a question regarding the rear end. I believe as of now its the stock 10 bolt 8.5" with 3.08 gears. This would have 28 spline axles correct? Starting in 88 or 89, GM started using 30 spline axles correct? Basically, when the time comes to go thru the rear, can I swap in the later model 30 spline axles and use a 30 spline carrier? I figure if I'm gonna upgrade to a posi, might as well go with new axles now.

I'm sure I'll have a bunch more questions, but I couldn't really pass the truck up f0r $500 with all the parts. Also has a TH400 and working 4wd. Motor is gone but I have a nice 355 waiting to go in.

Thanks
Nick