Depending on how long you've had this truck, its sometimes hard to figure what was done before and it shouldn't be taken for granted. I would recommend measuring valve protrusion as well as head thickness and piston height before bolting the heads back on. Also crushed head gasket thickness (as best you can). If nothing obvious is found, then check the oil pressure as noted. I know next to nothing about the type 4 cam but if some of the clearances above are off, the extra lift could be just enough to throw it over the edge where it wouldn't on an engine whose clearances were all correct.
Whoops, I didn't look at page 2 but my question is whethr this engine would run and apparantly run well, with cam timing off a full tooth... how many degrees is that? Anyway, we'll know soon enough I guess. Be interesting to see (for us anyway, Drew, you gotta be on the edge of hershey-squirting by now ( : < ). Good luck