Well I made a OS 52 out of a OS 48 and have used the engine for three years. I also have three other OS 52's and there's no difference in the way the four engines run.

However it would have been cheaper to have bought a OS 52 at a swap meet than to convert the OS 48. Now all I have left of the 48 is the crankshaft, crankcase, & bare head.

The guy that has access to a machine shop and milled down the crankcases on his Saito engines to increase the compression ratios made out OK. It didn't cost him anything.