Anyone know what might be making my spark plugs foul after 10 miles? they are AC DELCO hot 45's.....In case any of you are following, this is the same "newly rebuilt" engine that I put back in my truck in June....here it is October, and the &*^$% thing is still missing so bad I can't dri8ve it. Only missing on acceleration. Ran perfect last weekend after the mechanic set the timing, points, carb, etc....8 miles later on the new plugs, and they are fouled....any help appreciated