I finally got around to putting the gauge on the fuel filter bowl today, but I am a little confused.
Although the truck seems to be running fine, the gauge readings seem low.
Here they are:
680 RPM....30 PSI
1000 RPM...29 PSI
1500 RPM...29 PSI
2000 RPM...27-28 PSI
2500 RPM...25-26 PSI
I am holding off on shimming anything until I make sense of these numbers.
The vac gauge just prior to the fuel pump is reading only -5 at idle, so I don't think there's a problem between the tank and fuel pump.