by hennesse » Tue Sep 11, 2018 11:19 am
Mayday,
It would be disqualified from AMCA judging - wrong engine/frame combination. Knowledgeable K-folk would fairly easily pick up on the wrong frame, wrong triple trees. Wrong fork tubes - deduced from the above. If you have 19" wheels, they would be OK for a 1953 or 1954, but wrong for a 1955.
If the bike is a 1953 except for the engine, there will be a number of differences, some plainly visible (headlight bucket - position of indicator lights), some not so visible (different shocks).
Joe and Jane Public would never know - they've never seen a K-model before.
If you were to ride your 1953-frame, then a 1955, you would probably notice that the 1953 was easier to turn the handlebars, easier for a variation in the road surface (rocks, grooves, bumps) to turn the wheel. The 1955 would be more stable at speed - easier to do a "Look Ma, No Hands".