We had high oil temp on the first small block w headed engine we built , 250f oil 150f water ,on breakin - we found the oil was dark and smelled burnt after the first few min at 3000 to 3500 no load , it turned out to be that all the holes in the rocker shafts were not drilled all the way thru ,almost trashed a new set of offset rockers, changed shafts and oil temp stayed under 200