Thanks, Bob!I have a '66 Riviera 425. The fuel filter is mounted less conveniently just above the pump. I think mine is probably mounted correctly. The filter is a 3 line filter unlike the one you show in your kit, but similar to the one mounted high on the green engine. The third line is a return to tank. Not sure what the pump configuration is, but I will try to remember to have a look if someone else doesn't assist.
The filters on the two green engines seem to be mounted in the same type of bracket attached to the thermostat housing and the front view is a GM/Buick factory photo. Neither is a '66 though so maybe they changed the location like a few other things they changed.
What do you think about a Super Wildcat backed by a three-on-the-tree? Did they do that?