I have a 350 chevy with these modifications.280h cam,aluminum dualplane intake.headers.I have a 4150(750 dual feed). the problem Ihave if it is a problem is the motor seems to run rich.the exhaust smells real richI donot know if this is from the bigger cam or maybe too big a carb or possibly i need to upgrade the stock hei ignition.any ideas would be appriciated