Help on Fuel Pressure

[M-I-K]

Hello All from Italy!

i have a BDR COBRA with a Roush 427 R Engine


i have recently changed the mechanic fuel pump on my Roush 427R with an electric pump, using a direct line with no return (i.e. gas tank-filter-pump-fuel reguator-carb); the carb is a quick fuel 850.i have also have connected the gas line to the rear of the tank in order to not have fuel lacks in acceleration
The car works great and i have no fuel leak but i noticed that the fuel pressure on the gauge is not stable
The Pump (As the rest of the line and the carb) is brand new, and right dimensioned for the engine



when the car is cold is very high
becoming hot it goes down

actually i can say that we start from 11 (at the start) going down to 4 psi (very hot)

I thought that with fuel regulator and pump the pressure of the gas shold be the same always, and i do not understand the reason of this behaviour, maybe some one have suggestion/impression or even an ecperience to share, as you can understand there is not a lot of people here to discuss with regarding cobra and 427 engines.

Many Thanks