Swapping spider gears

[lilpoindexter]

Hello:
Im working on a '63 C10. I swapped a 5 lug front end from an '86 suburban on to this thing.

I bought a '78 C10 12 bolt 3:42 axle for the rear. I decided i dont really want 3:42's, and i have no welding skills to weld the perches on to this thing.

The original '63 c10 rear end is a 3:73, and its not in bad shape. i want to use the '63 rear end, but convert it to 5 lug.

Is there a problem using the spider gears from the '78 c10 in the '63 rear end to avoid having to purchase the more expensive 63-64 conversion kit with spider gears?