My cousin just called me. A friend of his has a 1941 Chevrolet 2.5 ton Army truck. The owner of the truck states that the rear main leaks alot!! The owner also says that the engine is a 270 cubic in. six.
1. Did Chevy make a 270 c.i. six in 1941 for
the 2.5 Ton Army trucks?
2. Is the rear main seal any different from the rope seal in a 216? ( 216's seems to leak alot )
3. Are there any replacement seals which work better that the original rope seal for the 270 c.i. engine?

The Chevrolet army trucks were 1 1/2 ton from what I have read and they used a 235 Chevrolet engine.The "heavier duty" trucks were GMC's and they probably ran a GMC 270 engine.A rope seal would have been used in the GMC and the engine is very different from a Chevrolet.

What happened with the '48 spare tire cover/shelf???

Chevrolet's Flint, MI Motor Plant assembled GNC 270s and they were used in "handed" i.e. opposite-rotating forms in the Cheveolet-built Staghound TE16 light armoured vehicles that were it seems mostly delivered to Canada and the UK. The 270 was also used in the Canadian Chevrolet C15AA and C15TA armoured 3/4 ton military trucks as well as the Canadian Chevrolet Fox and Otter armoured vehicles and the 3-ton GM C60X 6 x 6.