I have a set of 305H.O heads on my 350 and I was wondering if I should leave them on or change them out to my original 350 heads #3998993 with stock springs and valves? The 305H.O. heads have been ported, polished, 3 angle valve job, new 1.94 intake 1.5 exhaust valves, high lift springs (good to .510" lift) with 10 degree superlocks and it has also been 350 gasket matched. The intake has also been gasket matched and the camshaft has .470" lift intake and exhaust and 224 duration at .50".