730 and 830 are close, as Mel said, part numbers must be chased. I have found that the closest thing to the 630 is the 511b for triple range and 611b for COM. I have a very early 630 dry clutch triple range and lots in common with 511b except engine and front end tin. I think rear fenders are common too.
Case IH parts site on line is a world of help for part number comparisons.