Irepaired a blow head gasket. And now that its all back together it makes to much noice in the valves. I adjusted them down to 8 then back to 12 and it still runs bad and sounds bad like a diesel truck. what could i have did so wrong to make all this noice. if i am off a gear on the timing would it make the truck make alot of noice? ive put it on a timing light. any suggestions from anyone? thanks my truck is a 1984 B2000 pickup valves are adjusted at 12 right now and im running 10-50 oil. Todd