Originally Posted By Wicked49670dart
Fired up my freshened up 496 and ever since has a stumble hot. Plugs are light gray in color, I use VP 110. Idles smooth at 1200 RPM, but has stumble right of idle. Carb is a 4150 1000 cfm Pro-systems carb. Tried richer on mixture screws, still the same problem. Timing at 34 degrees. I did change the cam to 274/280 from a 268/272 flat tappet.

Primary Main 84
hi air 32
idle air 76
idle feed 35
PV 6.5

Thanks Matt
Did you degree this cam in off the cam card or lobe seperation angles? If not maybe it is time to do that twocents Light grey with race gas is probally a little richer than I would run it, try leaning the idle AFR down to see if that helps scope I've seen motors stumble both from being to lean and to rich shruggy

Last edited by Cab_Burge; 07/11/16 12:09 AM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)