[bobcowan]

Bigger lines are not really needed for 650'ish HP. 3/8" (-6) would be just fine. But, it gives you extra window of safety, and the pump doesn't have to work as hard.

I'm using an Aeromotive A1000 pump, with -8 feed and -6 return lines. Engine makes somewhere around 625 HP on E-85. The A1000 is kind of overkill, as I really don't need that much flow. But when I built the car that was what was available.

Over the last 8 years, I'v had the car flat beded twice for mechanical issues. Both were due to a failed pump. I'm looking to replace it with something more durable. At the moment, the Holley billit pump is looking real attractive. Holley claims it's a 100,000 mile pump. I'd be pretty happy with 1/2 that.