Any more commentary on push vs. pull? I am pulling through now with a KE pump on the pulley set up. Loosing fuel pressure above half throttle. I would have though my setup would support 650HP. All -8 with sweeping bends from the tank to the carb.

I pull through the setup I mention earlier with Mallory 140 electrics. Filter below top of tank and pump below filter.

Didn't one of the engines I sold you come with a stock fuel / water separator?
I drilled and tapped that one for 3/8 inch NPT fittings. There is enough material to do that.

i recently rebuilt a set of hp500 efi engines that were bumped to 600 hp in 2009 and the engines showed no sign,s of fuel starvation.i would not use the stock filter/filter head combo with anything over 600 hp.