Shortly after I got my 66 Charger w/383 back in 2010, it had just over 78 K original miles on it. I had the push rod issue. Being away from these cars for some 50 years, had to totally re-educate myself as to these 60's era cars. I was dumbfounded as to why it would randomly stall out while other times run perfectly. But since the stall out was quite random, it was summer, but thought it was just vapor lock issue but I had always managed to get it re-statrted and was on my way. One day, out for a ride, it stalled while driving and refused to re-start. Had to be flat bedded to a general auto repair shop that's just down the road from us that use for state inspections and general car repairs. He checked ignition, carb and all OK, replaced fuel pump & fuel filter but still had what appeared as a fuel delivery issue. He wanted to install an electric pump. Told him no..hang on while I started researching this issue on internet. Googling, found many threads and accounts that discussed push rod length in big block Mopars.
Me, not knowing that in a big block, a pushrod is what actually strokes he fuel pump, called the mechanic and told him about the push rod length to check it as might be the problem. He knew that there was a push rod, but not the possibility of excessive wear of the rod that could cause this. He obtained a replacement from local parts store, replaced it and all fixed. In my case, the push rod was worn by well over 1/4" of spec. just barely stroking pump !! In my research, there were accounts of Chrysler having this issue back in the day with push rods that were not hardened properly that made their way into thousands of big block engines. Also much discussion on replacements that weren't much better. The previous owner of my car had done an "engine refresh" in 2008, but don't think the previous owner replaced the push rod at that time.
Hey guys, beware of your length ! Speaking about fuel pump push rods I mean....