It's not a broken camshaft. The problem, as Doc put it, was with the rear cylinder of each bank. The likelyhood of two broken camshafts, on opposite banks, at the same time is unlikely to say the least.
The arrangement is:
It's probably a lifter that got stuck and gummed over the winter. Pull the valve covers and check for valve movement. That should take maybe 30 minutes max. I would guess it's the intake valves.
Any sort of crack on the sidewall or head should result in some movement of the compression gauge needle. It would need a gaping hole to have no needle movement. That usually means valves.