Just installed a wide band on the 68 at idie running 13.9 and cruse 12.5 but WOT 15.2 its, a 850 holley vacuum secondary. Fuel level is correct. Running 78 & 82 jets with rear extension. Light spring in secondary is all in at WOT.
Just thinking of going up one jet size and playing with the idle mixing screw on main would that help? Are is that to easy??
A little info on set up its a zz502. I am at 18 D base on timing all in at 3600rpm with #4 plugs AC DELCO.