12 Bolt Chevelle Posi Question

Hopeing someone can give me an answer on this.

1969 Chevelle 3959038NF
1970 Chevelle 3969278NF

I have a 1970 Chevelle 12 bolt rearend. I'm trying to figure out if the posi section from a 69 12 bolt will fit inside of a 70 12 bolt rearend. Both are Eaton. I'm just stumped on not knowing about the difference between a small or large ring gear. And whether it will work or not. Thanks to all out there. 20 hours to go.

Found out it's a large ring gear.

12 bolts all have the same size gear but the.. the GM carrier where set up for diffrent gears like a 2.56 and you would need a ring gear spacer or a thicker gear if going up to a 355 gear Non C clip pont .olds buick had 12 bolt cover but i think were a odd duck use 10 bolt stuff in them

Thanks Pat. Mine is the C clip style. I'll do some more checking on this.