Old FH race cranks ( before the 8BA )

[3W Hank]

Right now my 41 block is bored 3.5/16" or 1/8" over std ( relived ) but as cylinders is told be tapered I need hone and custom pistons. Another way is go next step up and bore 3.3/8" or 3/16" over std.
But to go 3.7/16" or 1/4" over std bore is tuff.
I dont mind get custom pistons, but a cool deal is old Jahns race pistons ( but hard to find - my guess )
The 1.5 mm rings is not for me critical, I can if I like get some tension out of older rings tech.

But a pre 49 idea and bore + 1/4" and stroke a 3.75" crank + 1/8" to 3.875" and that get me 288 cubic.

One idea is use a stock 3.75" 59AB crank, that get 278 cubic, and less work and less cylinder pressuare.

Light of the crank some weight and light flywheel/pressuare plate.
Ideas on that ?

I has a short nose big main and 2" rodjournal and the 21A rods.
I has also a std 59AB crank.
Somehere had a crank 'maybe' for sale to, stroked 1/8".