thanks for the input, I will try that rocker mod and check to make shure the rocker towers were assembled right. now the only question is what cam would be a good cam to replace it? not sure of the current specs, but i know it was a high lift and sounded extreamly healthy at idle. Early 20R head with a 22R block which have both been built to the max. It was made to use a 500cfm carb (i've got the holly 500, #4412 on it now) and it was ment to race.