2002 VP 5.7 GI A raw water cooled salt water. New manifolds,risers, water pump, lower inlet fitting. Six cyl have 215 psi and two have 180 psi. Idles smooth on muffs but overheats after 5 minutes. Overheats fast under throttle and load in water. Loopy idle in neutral at dock in water. 1200 rpm...