I road raced against 1st versions (`69) in soCal on my R5 350 Yamaha. They were too heavy stock in the corners and I'd draft them on the straights. We ran 250 to open class production bikes. Hondas didn't have a prayer against the Trumph/BSA 750 triples or the 750 Nortons. Steve McLaughlin was the fastest Honda rider then. He's the guy who started the World Superbike class in Europe. His dad was a Honda dealer in Calif.? Willow Springs Raceway was my favorite track back then.
Maybe these stripped 750 Hondas were lighter?