Gave up trying to adapt the 98-02 club cab seat mounts to the 79 floor and bolt pattern. Too many changes in elevation versus the flat floor of the van.
Unbolted the seat mounts from the tracks. Added a 4" steel strap to raise the needed height to a 3x3 angle. Cut out a bit of clearance for the track and presto a flat seat mount.
I have a plywood template of the floor with the factory seat mount studs drilled out. I can work inside instead of humping the seats or new mounts back and forth so they should drop in place.
