I have a1980 K10 w/1973 350 4 bolt main motor that runs rough when accelerating. I have replaced the plugs, wires, distributor cap, fuel pump, coil & module. Cant seem to figure this out. Ran fine one day and then rough the next. Anybody got any ideas?

 

What year, motor, etc?

 

Motor is 1973 350 4 bolt main - Truck body is 1980

 

Have you checked your timing?

 

Ignition timing or crank shaft to cam timing?

 

The heads have over sized springs, would that affect factory lifters over time? The heads were made for a high performance cam but I have factory cam installed.