Well, to give you some background... Great find!
The 228, 236, 248, 256, 270, and 302 gmc engines share the same basic design and dimensions. Some of the subtle differences between the engines are the flywheel. Some 270s had a six bolt flywheel. All 228s had a 4 bolt flywheel. There is a difference between the number of teeth on a flywheel for 6 volt or 12 volts. The bellhousings should be interchangeable.
If you were to put that engine in a 52, use the bellhousing that is currently in the truck, and find a flywheel from a 54-55 248. That should be a six bolt flywheel with the 6 volt ring gear... assuming your 270 has a six bolt 12 volt flywheel. You will then use your original starter with the foot masher.
Does the 270 in the machinery have a mechanical fuel pump? Some of the military blocks were not machined for a fuel pump. They used an electric one.
