I didn't see a mechanical fuel pump anywhere...I looked at the block and can't seem to find a block off plate as well. The fuel line comes from under the truck to the fuel filter and then to the carb. The PO rebuilt the engine a about two years ago. The smog pump was gone when I bought it for $700.00 about two years ago. If i crank up the in-line pressure regulater like you said to 3 or 4 psi..It fills the site glass all the way up...at 2 1/2 the fuel sits about level like the books says it should..After I replace the clutch...I will get that rebuild kit from napa like posted earlier and see if that will help. I have no power anywhere. The Cat converter is gone to..It had a cherry bomb muffler...but I changed that out for a used stock one. That thing sacred all the deer away...they knew I was coming with that skinney muffler.