So I thought I had exploded my rear but when I popped the cover off I had only just busted the cross pin for the spider gears is their any difference in the spider gears and cross pin between the 70s and 80s? Because I cant find a 70 for decent price

Randy's ring and pinion, yukon axle.  They would be my first calls for parts.  

 

If you broke a 70 and have access to an 80, put the 80 in.  I broke a 70 and if you are horsing around enough to break spiders, you are likely about to twist off an axle as well.  

How yall break axles and they live in my 24v is beyond me lol. Another option for parts is quad4x4

Quad4X4.com for sure.