Fuel Pressure Problem/Question

[72Rdrnner]

Hey Gang,

Had a problem with fuel pressure...there was none.

Tracked it down to a badly worn fuel pump pushrod (440 4bbl HP). It had worn down 1/4 inch in the 108,000 miles and 35 years of existence.

In the process I thought the anti vapor lock canister that goes in the line on 440s (mine has A/C too) might have been the problem. So I removed it, but made no difference.

Once I got the new pushrod in, I installed a fuel pressure gauge on the carb fuel manifold. The pressure was 5-8 psi which is what the FSM calls for. Then I reinstalled the anti vapor lock canister. Cranked 'er up and ran just fine...but the fuel pressure gage now fluctuates so fast and so far I can't begin to tell what the fuel pressure is .

I am wondering if this wildly fluctuating gauge is really caused by the anti vapor lock canister as it is vented back to the gas tank through the metered orifice (.060) that comes out the bottom of the canister next to the inlet line from the fuel pump.

If so, is there a better place to mount the fuel pressure gauge? Or is there a type of gauge that has internal workings to eliminate fluctuations of fuel pressure?

In the end it doesn't seem to be a problem as far as the engine is concerned since it runs just fine all across the power/speed range of the car.

Any insight or help will be appreciated.....

Then I'll move to the nagging off idle "flat spot" I have!