Two and a half years after purchasing a new rear petrol tank I finally got it installed Fri. There is some minor tweeking I need to do in the line plumbing, but it will have to wait until I get back from Stockholm.

In case anyone else is into abusing those scorned 109 two door Land Rovers the process is below:

Parts:
rear fuel tank, same as 109 four door
mounting bolts, sleves,& rubber grommets same as 109 four door
rear tank filler assy from 109 high capacity pickup
filler
hose
adaptor (goes into side of body to hold filler)
both access plates from bed of a 109 four door



Prep:
• re-route exhaust, making it the same as a 109 four door
• Second to last cross member has hole for rear PTO shaft. You need to cut the part of the cross shaft that bulges down and replace it with a steel plate.
• Cut off rear muffler hanger from frame
• right rear spring holder mounting to the frame needs to be shortened about two inches (vertical plate extends a little too far inwards on the frame). A trial fit of the tank can tell you exactly where you need to cut.
• de-rust and refinish the frame from the diff rearwards. The fuel tank will be in the way afterwards
• cut holes in the floor for the access plates. It is best to look carefully at the location of these plates in a 109 four door first to get a feel for where it goes. The sides of the plate will sit on stiffiners that go front to rear. Therear of both plates sit on underfloor stiffiners that go from side to side. For front support of the plates, I cut up the floor material removed from the holes and pop rivited them into place.
  The small access plate is in the rear covering the vent tube. the larger plate goes to the front and covers a vent tube and the sender/fuel siphon hose assy.
• Cut a hole in the bottom of the right rear tool box for the filler. use the filler tube on the petrol tank as a guideline.
• Cut a hole in the side of the body for the adaptor from a high capacity pickup. The bottom of the hole will be at the floor of the toolbox. The adaptor will fit inside the toolbox. The filler hole is lower than the one for a 109 four door so do not use that as a guide for locating the hole.
• if you don't already have one, install a fuel selector valve on the front of the seatbox. Additional fuel guage is optional. If you decide to add one, you need a series III fuel tank sender unit, almost any Smith fuel guage that should be connected to the guage voltage regulator.


Assembly:

Staight forward. The holes for the rear mount are already in place and the brackets for the front tank mounts are already welded to the frame. It helps tolook at a 109 four door rear tank to see how the mounting parts go together.

The hardest part is getting the holes in the correct place, cutting the access holes in the floor without cutting the underfloor stiffiners and radiusing the corners which sit directly on the stiffiners. I drilled a couple of holes from the underside to mark the edge of the intersection between the side to side and front to back underfloor stiffiners. I used a 3-1/2" cutoff wheel and went slowly. i also wedged a couple of screwdrivers between the floor and stiffiners so I could tell when I got through the floor.

After telling people I was going to put a rear tank in for almost 3 years, I figure I needed to actually do it. the doing is not as bad as it sounds as long as you carefully measure where you need to put the holes, go slowly on the cutting, checking frequently, and look at a 109 four door first, including taking off the access plates to see how they fit.