Mike,
If it is a 1955 first-series engine, it would have had a 6v flywheel/starter.
3733949 might be the 55-1st block casting number and 3835911 might be the casting number for a 55-2nd block. I think the engine serial number can be used to tell 1st series from 2nd series in 1955. That number/code is pressed into the block in the ledge just to the rear of where the distributor enters the block. If you fine that code/number, post it here.
Maybe someone will post better information.
Tim
