Good morning all, While I am waiting for my Manual to arrive,a question or two,on my 1987 OMC 4.3,recently aquired, sounds like Tappet noise I would like to adjust Valves, do I need to remove Manifolds to get the valve covers off? Do the Valves adjust as any other Chev,Solid or Hyd? As stated in previous threads this Boat runs and drives, after sorting various issues,heat was one,new Impeller back flushed and found One "Fin". New points/cond,Plugs,Oil and filter,carb rebuilt. Flame Ret. cleaned. This place has been a LARGE Help! Thanks to you all! Dave.