Bore it to 3 5/16” and be happy !
I ran several 59L blocks bored to 3 7/16, one is still on the road in a 40 coupe. It was built back in the late 80s and some of the pictures in my book are from that engine.
Gramps
Ron, i have a 59L block that was also bored to 3 7/16 and has a 4 1/8 stroke. The engine was built in the 50's by Reath Automotive in LA. Calif.