Yeah, I was gonna suggest you lost a cam lobe cam. If you by chance got a rocker arm to tight, or your new springs are stronger which is very very lickely, it put more pressure on the old cam than it wanted and you chewed off a cam lobe. If so, all that fine metal is now running threw your motor oil and likley thru your bearings. Hate to suggest it, but if this happened all of a sudden, and not immediatly after your turne up as if you got the firing wrong, and you're positve the fireing order is right then the lobe it my first suggestion. Sorry dawg, hope I'm wrong.