doobspanel - From what I have found the OEM specs for 1950-1951 Trucks and Cars, 216 or 235 is as follows:
Vacuum Spark Control: Delco-Remy No. 1116043
Plunger Travel: 17/64"
Eng. Deg. 0° at Vacuum (" of HG) 7-8.5"
Eng. Deg. 20° at Vacuum 16.5-18.5"
There is practically no difference in compression, combustion chamber design, and cam specs to later engines. I would shoot for these numbers to start with. I believe all of these specs are PORTED vacuum.
Paul
