texacowego,

First. let's find out if you have a flathead engine. Are the sparkplugs in the side of the head or on top of the head?

Here is a flathead in a Chevy truck (check the first link). And a discussion about the possibilities. The truck did not sell and a week ago it was relisted with a 292 engine, I think.

http://www.stovebolt.com/bboard/cgi-bin//ultimatebb.cgi?ubb=get_topic;f=2;t=004406#000000

Tim