The GMC engines of the 1950's thru 1962 have more power and higher rpms than
the 40's versions. All are long stroke and will not take being over-reved
for long. Even a 50's 270 has more hp typically 145 hp. The block may have
stayed pretty much the same, but the pistons and the heads changed
The one thing to look for on a 270 or 302 is the front motor mount. The
earlier ones had the 'foot' on the plate behind the timing chain cover.
These are easy. Later ones had motor mounts on the side, one behind the
generator. These do not have the 'foot' and are more of a challenge. They
also had more hp
The cid of the engine is the first three digits of the sn stamped into the
flat spot behind the dist.
The M211 had basically the same axles (wider) and center gear carriers as
the ww2 CCKW Banjo axled truck and utilized the MIL GMC 302. The MIL 302
was rated at 145 hp as I recall. The civy ones up to 160 hp.
The MIL GMC 302 is much more of a challenge, if not impossible for a
replacement in a CCKW due to the front end differences. In a CCKW, as
opposed to a DUKW, there is no room to play with fore and aft.
Steve AKA Dr Deuce
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