Whats the deal with 340s?

All engines get that "ring" at high rpm. It has to do with the exhaust pressure waves at those rpms. If you haven't heard it you're not revving ti high enough...lol. Most engines it's beyond 7K.

Horsepower a) is an abstract unless it involves tying weight to a horse & b) is only effective when harnessed properly (pun intended).
My point remains - the as-factory-assembled 360 is "easier to harness" with parts the vast majority of enthusiasts will be ok with running and living with on the street. The 340s were baddasss but needed steeper gearing and a better convertor if it was an auto to really shine. The comments are regarding horsepower at high rpms in a competition engine. Next time I hear the Acura next to me idling with a turbo'd Indycar V6 or the car at the cruise night has one of Coughlin's engines between the fenders I'll consider those comments relevent. Otherwise they're just pizza shop too-many-beers BS benchracing.

Give a core to a good builder and the top 3 (318,340, and 360) can be made to whatever power level one needs.