Hey i have a mild 318 and we took it on its 1st test drive for bout 10miles.And it always stumbles and acts like it misses.When at WOT then let off it stumbles,then once you get it where you want it goes ok.And when you first start out(0-40mph) it seems like it doesnt want to go anywhere,and i have open exhaust.And i dont think the tranny is shifting correctly to its mph points.At 80mph it was at 3500rpm.But one reason is because the secondaries arnt opening all the way(close to 1/2 way).And its running rich(plugs are all powdery black).Do you think if i got a 4bbl bracket and made the sec. open all the way and lean it downa bit,would it drive better?
thanks

 

sounds like the carb is dumping fuel or just to big the motor. How big and what kind of carb? When you say mild how mild are we talking?

 

Yeah, the carb sounds like it's too rich. You want it a little on the rich side during break-in, but not to the point where it doesn't hardly run.

What carb are you running? What are the jet and/or rods are in it? Are you sure the timing is close?