I took my truck out for its first drive yesterday and ran into a problem. Whenever I get above 1500 RPM the engine starts popping, alot. I checked the valves, set the timing, and made sure the carb was set right. On a hunch, I took off the vacuum advance and plugged the line, and the engine ran much better. I could drive the truck and it had no problems revving right up past 3k, with absolutely no popping. I can't figure it out, any ideas?
The engine is a '58 235 with hydraulic lifters.
