[Prowbar]

Thanks, James. Forgot about those posts. Good job on the data.
Your cam lift measures a lot more than mine, didn't think mine was all that worn. Not sure now, maybe the cam lift was revised a couple of times. Have to measure my 305 now also to compare.

Seems like more lift definitely helps.
Will talk with the cam grinder about how much I can safely improve the lift.
More seems better but I would have to probably change/modify the valve springs also.

The stock ones are lousy on seat pressure, maybe 50 pounds, maybe shim them for improved pressure or change them for another spring.
They are good are break-in springs, though.

I left the stock exhaust duration as is, the exhaust port on non-Magnum heads is pretty restricted, not much can be done about it I think.