Hello,
Doing a restore on a 91 K75. I'm about to put the fuel pump back into place. Looking to confirm what I believe is correct so please correct me here.

Believe the two downward facing spigots on the front left of the tank are for the fuel going down (the second or nearest to the back), and the return pipe (forward of the two). Interestingly the two tanks I have for comparison have the front most spigot (return line) going to different locations but basically both send the returning fuel to the front of the tank.

The two spigots on the right side of the tank about midway back are both over flow tubes. One from fuel input cap. If you put too much in and it gits up to the top of the input then it is sent outside of the tank. The second one seems to do the same but in case the level inside the tank gets too high then it could be shunted out. I suspect the differences I see in the tanks have to do with air quality issues back in the 90's in Calif. Main difference I've seen is the manner of handling the return fuel, i.e. the forward of the two tubes in the front left. In both cases the returning fuel is sprayed to the front top of the tank.

One question though, on one tank the overflow tube for inside the tank had a black plastic extension. Just a piece of black plastic tubing over the inside port. Is this common? What was it supposed to do?

thanks
best regards
jjefferies