Rob, the new holley pumps are bad azz. But I can buy a pump that's just as good for $300 less. If you run the higher pressure pump and want an easy install don't use a regulator just get an Enderle by-pass valve and put it on the return line. Only cost around $45 and a better way to regulate the fuel really.

Thanks guys.

I don't have a return port on my tank so it's either an in line regulator or a pump that works at 7.5 psi or so.

Is 7.5-9 psi too much for the needle and seat on a 4150?

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Thanks MT.
Would you recommend an in line regulator with the Teague pump in the link then?

The needle/seat/float will usually tolerate 8psi, or even 9psi sometimes. But, if you boat in rough waters, you may find the needle coming off the seat very easily when hitting waves with the fuel pressure that high.

put them on a west coast dyno and they sure will be.this was for sb.

I'm also a fan of electric pumps w/ regulators returning to the tank.

Interesting , tell me more, something you`ve used and have experience with?

no,the needle and seat will hold up to 11psi and some up to 12lpsi.
you can cut a fuel fill hose and add a return there.thats how mine was for many years till I got my new tank.

Not much to tell just make a complete loop with the your fuel line and put the valve on the return. It really cleans up the look and your not relying on a small oriface to supply the motor with fuel. I've used them in the past my current setup I have a blp regulator on the end of the carb fuel rail.

Keep in mind, additional pressure doesnt mean you will get more fuel to the engine. There are many different styles of Needle/seat assemblies, float designs, and so forth. Each setup can be different as far as the pressure they will tolerate.

If everything is properly setup, 7-8psi of fuel pressure will without a doubt, support well over 1000HP. With a single carb setup, say a blow thru, I dont care how much pressure you throw at it, once you get to 1150hp or so, you run out of needle and seat area. Hence the dual needle and seat bowls become more needed.

For a guy building a 600HP, 700HP, or 800HP engine, I think we are getting ahead of ourselves a bit.