Found part of the problem (pic) :D

Tore into the 72 Swinger engine in car the wife bought the other day and found 15 big bumps on the cam.
All except that last one :D

Try and see the top of that lifter.
It was opening the valve about 1/8 inch, and I have a feeling that kinda messes with the duration too. :D
It must have happened fairly quickly because from looking at the oil and travel marks it looks like it was traveling more than that recently.

Someone: "What's the duration on that cam you got in there?"

Me: "About 6 with a 80 thousandths lift. :D

The heads are coming off next to see what we see in there also, but this is as far as I got after my normal work today.

I'm going to need a cam (good used would be ok if anyone has one they want to part with)
Will do the timing chain and sprockets with new.
If the valves are ok but just need a touch up I can do that here.