ABOUT HOLLEY FUEL PRESSURE REGULATOR

Where should the regulator best be fitted?
in the engine bay? or beneath the fuel tank?
It is a 1-4 psi one. How will I know what pressure it sends to the carbs? (is it 1 psi when CWed till the end and 4 psi when CCWed?)
thanks in advance guys.

You need to put a gauge on it(with a brass T) temporarily while the engine is running to set the pressure properly. You can put the regulator in front or in back, it really doesn't matter. easier to adjust it though if it's in the engine compartment.

As an aside, be VERY careful where and how you route your lines. All pass-throughs MUST be grommeted, and make sure the fuel lines aren't near anything hot or spinning(like the backside of the fan). Failure to do this results in a pile of burnt car.

It can be mounted anywhere "between the fuel pump and the carburetors" Most people mount them in a convienent spot for monitoring

The only way you're going to know the actual output PSI is to buy a guage and put it in line with the fuel being delivered to your carburetors.

If you have dual Weber carb's, they like around 3.5 PSI

Mounted my Holley regulator on the engine compartment firewall, just before the fuel line splits to go to each carb. Mounted a gauge right next to it. You may need to see the gauge when tuning/balancing the carbs, so with this location, it's all right there.

If your running an electric fuel pump buy the correct low pressure pump. One less thing to leak. When it comes to fuel lines the least amount of fittings is best as you have less chances for a leak.

Just my $.02