I put one on my boat that was border line.455 olds I was goin GPS 58 5k RPMS and it slowed me down to 54 GPS 4800 RPMS and loaded way more water Im assuming into my motor cause I didnt know to turn down water pressure from non loader setting. the extra water pressurer milkshaked motor and wasted the bearings!nocked hard seat out of head ,bent the valves on one cylnder & banged uopthe piston beyond repair. Total rebuild right now. BE careful! find out everything before you try it.
my 02 cents
was $1200 mistake for me.
Casey