Rear end side gears

[PRO-7 racer]

Recently I came across an early (81-83) small axle rebuilt rear end but my car is an 85. Can I just take apart the early rear end and put in 84-85 large axle side gears? Are the side gears the same for both early and late except for the difference in axle spline size? I realize that I will have to reset up the rear end and take measurements after the swap. Is it also possible to use the side gears from an open late model diff? I'm only planning to swap out the pumpkin not the whole rear end assembly. My current rear end is an 85 GSL model not an GSL-SE.