I can tell you with factory units there are two size centers. The first is the smaller one which you can go up to 4:10 the next unit goes up to 5:38. You can put larger gears on a small unit with a spacer. You CANT put smaller gears on a large unit. I would think spools are the same, but Im not an expert.
I had a 488 gear on a spool. I had it changed to a 410 gear. I was told, and if you can find one, they make a 410 that has a thicker gear set that will fit the next series spools or diff. I don't recall the mfr.