Back in the '50s I had a couple of 226 flathead Ford engines...a '49 and a '51 and I rebuilt them both, with moderate performance up-grades. Both were dependable and sounded great with headers, duals and Smitty's.
I also know that there were other versions of these engines for trucks, with larger displacements, but have no experience with them. I also don't have any references with truck data. Does anyone have any experience with those engines and do you know what is their potential for street use?