FI M50B28 stroker with b20 non Vanos head?

[haCR]

Hello there, I would like to build m50b28 for turbo aplication this winter. Now I´ve been running m50b20NV on HX35.

engine partlist what i´m gonna use :
M50b25 iron block
m50b25 NV rods
m52b28 crankshaft
m52b28 pistons
and
m50b20 NV head?
Dual 240° cams

Did anybody use m50b20 cylinder head on the b25 iron block for turbo application? Do you think it´s a good idea? I know that the diameter of the valves is like 2 mm smaller, and the head itself has poorrer flow compared to b25 head. I´d like to hear some numbers ... b20 head against the b25

Anybody?