[D111]

Purchased a new quick fuel carburetor to replace my 770 Holley on my Roush 342.

Engine now idles better accelerates very good .Sparkplugs went from a Wet looking black to a light gray especially the two center ones on both sides.only continuing annoyance is when I let off the accelerator Or downshift the car While in gear starts tugging, more noticeable when I come closer to a stop.
I just tried to make a video but it didn't come out well.
Did not have this At all with the Holley which deftly was running richer.wondering if anyone would know A possible reason for this to Occur? I'm not even sure if it's the carburetor.

Even when cruising When I let my foot totally off the accelerator in gear it slightly starts to occur then gets progressively worse as I slowdown for a traffic light etc.

If you think a video would be necessary I will try again.

Think you
Dennis