Fuel Pressure Gauge Location

I finally got around to getting an electric fuel guage, I wasn't crazy about having a fuel line in the cab, and I haven'
t gotten the back up tbi rebuild to my specs yet. I am wondering if there would be a difference if I would tap into the fuel line like the factory repair manual said to do at the filter, against installing a gauge at the back of the tbi?

I know that the electric may not be as accurate, and untested but I think that the fuel pump is the original pump and is about to go so I am trying to get a quick and easy way to see if the pump is still putting out. I do have a plan to install a standard mechanical guage at the rear of the tbi, but Murphy has let us say, thrown out a few speed bumps for my plan.

I am assuming that, since this is a stock 1989 GMC V1500 4x4 Suburban 5.7 liter with nothing more other then 33" tires on it, that there shouldn't be a real difference on the read from one location to the other, but like I said 'I'm assuming'. What say all?

There really shouldn't be any difference in pressure at any point between the pump and the FPR.

Yup!

All the test gauges go at the fuel filter because there is no fitting near TBI unit. There is an adapter to put in line at TBI for a gage available.

That would be pump pressure and not injector pressure correct?

No, it will be the same all the way to injectors, then regulater and return pressure should be 0 PSI. This is why you need high pressure line from pump to TBI unit on conversions!!!