

My 1981 318 runs rough/stumbles after warm up (about 20 min) particularly 1000-1500 rpm progressively getting worse. In neutral revs are fine, but in gear is when rough run warm occurs.
318 is just rebuilt, new Edelbrock 1409 carb, new exhaust manifolds/risers.

Have confirmed:
-electric choke working properly & consistent 12V
-fuel line stays cool, not vaporizing fuel
-fuel pressure consistent 3.5psi meets carb spec
Any thoughts or suggestions appreciated!
-Marko