Extra hp out of my 340.

Sorry RAMM. What YR said. For an engine that was totally gone through and has a .500" lift cam it's down on power. Could be tuning. Could be something else. It sure isn't the calculations. If there's a chassis dyno losing 30+% because of driveline loss the dyno's broken.
If it were me, and I owned the car, and saw the cam card, I would be tuning the hell out of it and if it didn't improve digging into it over the winter.

I don't actually care what the percentage is--I have very little faith in chassis dynoes anyways--they are only a comparator at best. As usual communicating over the internet is a clusterfuck. My point was that my observations are just what I said--about 90-100hp less on a chassis dyno than an engine dyno-BFD. I've seen extreme examples of a chassis dyno showing 150-200 HP less than an engine dyno. What I haven't seen is only a 50 hp loss ever.

Besides the OP states that he doesn't really know much about the engine and judging from that cam card if a 340 can't make 1hp/ci I'd be VERY disappointed. J.Rob