Number Series / Std. Cub engine differences

[Mamachala]

I was wondering what the engine differences are between number series and a '54 cub? Are the blocks interchangeable, what about hyd. pump opening,radiator fan mounting? I've heard the 184 has a bigger carb, are the manifolds different? The number series have dome pistons, do they also have a different cam? I know they run a higher rpm, is there just a different spring in the governor or is the cam also ground for a higher rpm power range?

I'm going to rebuild my '54 cub engine and thought I might use some of these improvements while i'm at it. Any other thoughts and advice are appreciated.

Thanks

Jack

[John *.?-!.* cub owner]

domed pistons, cam, governor weights, manifold, carburetor. Those are the ones I can think of off hand, may be others.