If you would like to ID your engine (someone might have changed it a few times over the years), find the codes shown on this page and post them here. People will show you how to interpret the codes (and will show you on-line resources that will be useful to you).

Here are a few useful resources:

1948 Chevrolet Specifications

1948 Chevrolet Truck Operator's Manual

1948-1951(1952) Chevrolet Truck Shop Manual