So, I started to troubleshoot why I had white smoke coming out the exhaust, today. Thought it might be bad valve stem seals, a blown head gasket, or something along those lines. After pulling the valve cover off the right bank (1-4 cylinders), I noticed something that made my heart sink: The number 4 exhaust pushrod was bent at about a 25 degree angle and laying up in the valve spring galley about 3 inches from its guide hole. The rocker arm bolt was backed out about 3 threads and the intake-side rocker was almost as loose, but the pushrod and lifter were still intact.
Pulled the corresponding lifter and the crown was trashed. Completely cupped about an 1/8 inch. Pulled the head and found no PTV contact had occurred, but, I fear the cam lobe is shot. Haven't pulled the cam yet, though. The rest of the valvetrain for both banks checks out fine.
Have an opportunity to source a cam and lifters out of a '77 F150 with a 351M, completely stock. Trying to get by on the cheap
for now. Just gotta keep this thing on the road until I rebuild the other motor. So, two questions:
1.) What do think happened with the #4 cylinder? Maybe, the rocker bolt came loose?
2.) Does the '77 F150 cam have the same specs, more or less, as my Bronco? Gotta pass emissions.
Thanks again, guys. It's much appreciated.