A stock '37 has a 216 but has a different style clutch, bell housing, clutch fork (with different spacing of the fork ball), and stomp starter linkage and spacing of the starter pedal, than the '41 and later 216s. So, if you want to stay stock it may be easier to rebuild your current engine. If you are going resto-mod then maybe better to find a 235 and redesign for the above items. I don't know whether later 216 cam and lifters can be dropped into your 37 engine but that should be investigated.
Kent
