well heres the deal, my 351w, has been having smoking problems for a while, i purchased the engine off of a friend. when he first got it the heads needed a valve job and that stopped the smoking, fast forward a couple years and its smoking again, and some of my spark plugs have heavy oil caked on them. my other friend who worked at the shop where the motor was built says its the valve guides and always has been. the heads are pro topline 200 cc aluminum heads. my question is do i get the heads fixed? or just try and sell them and buy new heads? if it were my engine i would have purchased AFR heads. if i go with AFR do they make a 200cc head? i know the oil on the plug can also be piston rings, how can i make sure that the valve guides are the problem? the car seems to cut out during acceleration and doesnt seem to have the power it should have. could this be causing the car to run rich? any help is greatly appreciated.