The 340 cam is about as "tried and true" as it gets. Although thanks to
@krazykuda and another member Oregon Cam Grinders now offers the 68 340 4 speed grind. It is a little healthier than the 69 and up camshafts that were all the more docile automatic grind. I think it varies by only a few degrees, but that's nothing. It's a dead match as far as I'm concerned.