[455-4+1]

I put them in the iron heads on my sprint boat.

Main reason was to get the oil back to the pan quicker and in better condition(6000 rpm for 60 seconds requires a bit of oil to return to the pan)

Blocked the rear 2 drainbacks on each head and installed -10 fittings at the rear with -10 hoses to the sump

Most of the oil in the heads now drains back to the sump without going past the cam, rods, crank etc. Direct path to the pan and no airation of the oil on the way back down