[Grady Clay]

Peter,

There are a couple of issues here.

First, the ’73 and earlier cars have the wiring harness below the filler where the ’74 and later have much up on the side of the inner fender. This allows the later filler neck to set lower.

The second is that there is a corresponding change in the filler neck starting in ’74 from 901.201.015.20 to 911.201.049.02. (There are some more part numbers between ’74 and ’89 [-03, -04, -05, -07] but I think the basic filler necks are the same, the changes were breather and vent fittings.)

The best solution is to use the ’74-> filler and carefully reposition the wiring to alongside the filler neck. I have used the earlier filler neck but the wiring still must move. Using the early filler neck leaves the rubber hose with a slight bend. If you do this, add a second pair of OE clamps. Some have had the neck of the tank repositioned but I don’t like that solution.

Are you moving your fuel pump to the front at the same time? (hint)

This will give you the excuse to clean and do some rust prevention where the filler neck enters the trunk and at the fender.

Best,
Grady

BTW, A few weeks ago I usurped your signature line and modified it slightly: “If you don't have time (or money) to do it right, how do you find time (or money) to do it over?” Great line.
G.