Any 235 will fit a 46 truck.
Depending on the year of the engine you may need to drill the front plate for the front mount.
1960 and later will need throttle linkage work
(see link). 1955-62 engines will need water pump conversion work of your choice
(my choice). 1946 truck has the exhaust dump straight down on the manifold, all full pressure 235's have the exhaust angle back. This will require head pipe work, or using the 46 manifold.
