BHD

Stuck lifters or broken camshaft could be culprits.

Rick 12v CTD

If you didn't reset your valve lash correctly when you changed the HG you could have had a piston hit a valve which bent the pushrod. On the pistons with the bent pushrods I would check to see if the valves are bent as well. There's a good chance they are.

I don't see why a tappet would stick out of nowhere but anything is possible.

If the cam broke, it would have been caused by one of the timing case bolts or the dowel pin falling out and getting wedged between the gears.

Also, check to see if the crank gear has slipped on the crank. There is supposed to be a visible keyway locking it in place but I've seen the gear walk off the shaft enough to cause it to slip.

j_martin

Looks to me like you tried to start it out of time and valves hit pistons. You're probably going to have to at least pull the head and replace bent valves, and maybe other damage as well.

Hoping for the best, but I'm afraid you just discovered that short cuts often have pit falls in them that totally wreck your day.