Most places say torque the heads 70 ft-lbs or so, but I got an AERA technical bulletin about how ford now torques the top bolt about 5 ft-lbs more than the bottom due to our intake manifold mounting style. It mentions that since our manifold bolts straight down, it has a tendency to wedge the heads outward near the top. It mentions that AERA members were reporting lots of blown head gaskets on the top side of the head. So their recommended torque is more like 70 on the bottom and 75 on the top. Has anyone heard of this?
On another note, does anyone know if it's safe to re-torque ARP head bolts? I know their torque value is for 75% yield, so it seems they should still be far enough into their elastic zone to be torque multiple times. I heard they say you can do it 3 times. Is that true? Obviously I would need to replace the head gaskets if I remove the heads, but I hate to buy all new bolts again.
On another note, does anyone know if it's safe to re-torque ARP head bolts? I know their torque value is for 75% yield, so it seems they should still be far enough into their elastic zone to be torque multiple times. I heard they say you can do it 3 times. Is that true? Obviously I would need to replace the head gaskets if I remove the heads, but I hate to buy all new bolts again.