Dan (and others) -
As to the MAF v SOR aux tanks, there are several differences:
1. The MAF tank does not have a transfer pump, the solenoid that operates it, nor the bracket/hardware required to mount them. You've got to find your own;
2. The MAF tank does not include the fuel pipe (77109-60052), a significant piece of hardware that would be required after the stock piece is removed (though, you can take a hack saw to the original and make it work);
3. The SOR package is not an 80 set up at all, rather a UZJ105 tank, straps, and filler neck. The tank will actually fit an 80 quite well, but there are fitment and operational issues with all of the pieces in an 80.
4. Neither package has the sub tank switch.
5. There is no known interface for either of these tank packages that will allow their smooth integration into an 80. In other words, the U.S. spec ECU apparently does not understand "sub tank speak," though there may be a few surprises here, as the U.S. spec 80 (97s anyway) have the sub tank harness...
6. Neither is a "bolt-in" project, to say the least.
Do you have anything on that fuel pipe? (77109-60052)
Still, the MAF offering strikes me as a better deal...
Cheers !
PS: This digresses considerably from the Kaymar bumper issue, so I am going to start another thread that repeats this post...