Hank, It is a Model 4160, P/N 05100-8007, 390CFM Holley with the "red cam". As I stated in my 1st post the "real problem" is after staying at idle for about 2 minutes the smoke is pretty bad and greyish/black in color . Again the smoke goes away after the initial acceleration and only returns when I idle for a period of time (1-2 minutes). If I drive around town for a day or 2 at 30-40 mph rpm 1400-1600 without opening 'er up...when I get on it she will leave a small greyish-black cloud behind me for a few seconds then it is clear. I am jet engine guy so please be patient with my carb terminology...if a "double pumper" has 2 fuel bowls (front & back) with a balance tube in-between...then that is what I have. The mech has lowered the jet to the smallest size (jet's don't affect idle do they?) reset timing to 8 degrees BTDC and idle to 850-900 rpm. She sounds great at idle just can't fix the smoke! Any more thoughts/ideas before I spend $90/hour would be appreciated.
