welcome. are you wanting to put G30 Suspension under a G20, or is it a G30 and you want the G20?

Most RV's I have seen were G30 conversions. Easy enough to check, as the G30 Had 8 lug at all 4 corners and a full floater 14 bolt rear axle.

For what I know, converting from 1 to the other isn't too bad. Easiest method would be to swap the entire subframe in the front, and the Leaf springs and axle in the back. I am not sure if there is anything else different.

[Linked Image]