Hi Ed,
Not sure if you were asking me or not but either way I'm a bit embarrassed to say I don't know very much about the engine I have other than it is a GMC Straight 6. I am assuming that the in-line 6 was original since the truck still had the 6-volt positive ground battery and oil bath filter. But over the years once I found out what the Hydramatic emblem on the side actually meant I realized that the previous owners had definitely modified the truck as it now has a manual transmission and a poorly crafted hole in the floor board where the stick shift now resides. Knowing back yard mods have been done I can totally understand why I ended up with those three dash fires.
Not knowing what engine I have makes me want to get out there and pull it. Part of my original plan is to put it on an engine stand and rebuild it myself back to full working condition. But I don't have any intention of putting it back into my truck. Part of the reason why I've joined this site is to find out what I should do with any of the parts I pull off. I hate throwing large items away that will just go to the local land fill especially if there is any chance that someone else might want them.

Sam

1956 GMC 1/2-ton
"Time to start the dream"
In the DITY Gallery