340 K Member ??

Observation... I might be wrong, but isn't a 6 cyl K-member totally different? You can't drop a V8 into a car that had a 225 - wasn't there even something slightly different between a 318 K-member and the 340 before '73 ('73 and up changed the motor mounts). Would the washer thing have something to do with that if there was a slight difference - or was I dreaming about the slight difference between 318 and 340 mounts.