Hi Jeff, welcome to Chevy Chatter II,
The block number - 837591 - indicates a 1935, 206cid motor.
The serial number indicates is was assembled in Flint ( 1 ), a 1/2 ton truck ( EB ), with the assembly done in March ( 03 ).
According to the Master Parts List, the transmissions were the same for the 1934 and 1935 models, but the Service Bulletin for 1935 shows that the engine mounting from '34 to '35 is different. I do not know if any of the later model engines will "bolt" into place.
What part of SE Indiana are you in? I'm located in extreme SW Ohio, closer to Lawrenceburg, IN than Cincinnati.
Good luck with your project,
Dan