My 79 F150 4x4, purchased before this last Christmas has had a noise like an exhaust leak. I put in my vacume gauge, and showed a bad vavle problem. Put a dollar bill into the exhaust (true duals/headers) and showed to be the left enging bank was the problem.
Removed both heads and fou a burned valve on the left side. Finally the question. The truck for the most part is a Hienz 57. Engine is supposed to be a 400, but I really don't know for sure. Heads are going to a machine shop this week to be gone through. Also found a bad lifter, and thinking about installing a hotter cam. But I'm not sure what the engine is for sure.
How can I find out what this thing is for sure???
Bob