Cylinder / case matching

[pmc57]

What's the go with matching cylinder transfer ports with crankcases. I'm in the middle of building a spare RM250A motor from parts I've had hanging around and thought I'd give it a bit of extra go by matching the cases with the cylinder transfer ports. Apart from matching the barrell ports with the cases, do you also alter the cut-away of the piston so it too matches the cut-away in the lower cylinder sleeve where the transfer ports are?
Any tips or advise with this type of mod would be appreciated.
pmc57

[Lozza]

While in the overall scheme of things this accounts for 3/5 of SFA what it does do is let the engine come into phase faster, so if your 250 is destined to make 30hp it gets to 30hp faster.Don't touch the piston.