Not sure where to begin... I have a 54 stock 235 (stamped 55 on the block) She was runnin' kinda funny - cuttin' out an such The engine started fine and idled great but was running very ragged. Thought it was the dist/timing or something in that relm. So I took it to a guy... He replaced the dist. set the valves & timing. After driving for a short distance, it seemed like she had a lack of power. Got on the freeway, felt like there was some kind of rpm limiter. after a few miles I continued to loose power. Traveling at 60 mph then she continued to drop until she got to about 40 then a loud whining sound an' then she up an' quit!. Any ideas before I tear into her? This truck until it started to run rough had plenty of power and was running great. Plenty of oil in her an water was where it should be.
Also when she stopped, there was a lot of smoke coming out of the valve cover.
[Had her towed and she didn't like none either.] Thanx It is a along intro but the bottom line is where do I begin?

Try prayer as the first response rather than a last resort ...