The problem George is that those durations are only useful for comparing with other Chrysler cams.
We've discussed this in some threads with
@Wyrmrider @crackedback and maybe @krazycuda
Chrysler, even in their promotional stuff and DC tech bulletins always put that out there. They never realy explained why.
From the actual cams measured, and from what Wyrmrider had seen working in the field, Chrysler degrees are based on the ramp change on the drawings.
IIRC there are enough original and aftermarket standard 340 cams we could come up .050 durations and estimate an .004 duration.
There's not true for original '68 manual transmission 340 cams. IIRC Rob had some measurements he has shared from his notes, as has Karl.