SH with H engine

Recap - I own a "53 super H, number 540J.

Engine has no c-164 cast into the block.

Cast into the block above the filter housing is the following - 6695 DE. (am told this is the cast code for the 152 block)

Below that, also cast is 2-BE. (not sure what that is)

Serial # prefix is IBHM. The "I" looks like an afterthought, or separate stamp.

Here"s the better info. I can now see that the date code is 9-9-M. I previously thought it to have an x code.

If I"m correct, the M makes it a "43. There is olive green paint under the yellow, which is under the red!!!

Question is this - could it be a war year power unit?

I"m sure it"s been rebuilt at some point - runs too clean. Can you make a 152 into a 164? Originally more than just a bigger bore in the supers, no? Crankshaft, bearings, etc... I guess I won"t know unless I open it.

Just can"t see why someone would put a 152 block into a super H. Why not rebuild the 164? Unless the block was shot, then it"s availability I guess.

what about the carb? I've never had it off, but I'm almost positive it's the super h carb on the smaller engine. The choke lever is on the engine side of the carburator.

Does it matter which carb you use, or is the bigger carb for the bigger engine? What would happen with the big carb on the small engine?