73 chevy 350 issues
 

rebuilt long block installed 3 weeks ago, new intake and carb from Summit, HEI distibutor, wires, headers, exhaust, oil pump, fuel pump.... basically everything should have been an easy install. Developed rocker chatter within 30 miles, discovered 4 rockers were loose, 3 damaged push rods, replaced them, back together running good. drove close to 500 miles, chatter came back strong, discovered 2 studs backing out of the head, replaced the head. back together, an't get it to run right, discovered the intake manifold wasn't true on the left head (the problem head), replaced the intake, again. Now it is all back together, running decent, put it in gear and it dies. Start tweaking the timing, it is now set at 10 degrees btdc with the vacuum advance pulled and plugged, idles good, put it in gear and it still tries to die.....connect the vacuum and the idle goes way up and runs way fast. The valves were set according to the Haynes manual, 1 at a time, in firing order, turning engine by hand and tightening until you can't turn the pushrod with your fingers, then tighten one full turn.

Could the valves be too tight and causing these running issues ????

had similar issues while dropping a 350 in a '32 Ford Coupe. do you have hydraulic lifters? we had to reset and re-check the valves at least four times before it started to do what we wanted it to. for some reason the last time we pulled the valve covers off and started to tighten them they were all completely loose and no where close to where they should be. also had to back the fuel pressure down quite a bit and put a regulator on it, but that was an external aftermarket pump.

Dont do a full turn, just do half. That may be your problem.

I have always tightened the rocker until the push rods can just be turned by hand with minimal effort, but definite drag felt and then 1/2 turn beyond that to set them. I think you went to tight as well.