When you relocate the battery, this is also the right time to ditch the fuel pump resistor and just run a wire right off the pos terminal of the battery to the pump with a 30A fuse and a relay.
Here is what I do:
First relocate the battery to the rear and setup a good ground to the - lug on the battery. Now that your battery is in the rear you will only need a small amount of wire to get the + lug on the battery to your fuel pump(No need to run a wire all the way to the front of the car just to run it all the way back again.) Set this wire to have a 30a fuse inline and a relay. I keep these in the box with the battery The relay will also pull a ground and the fuel pump control wire has to be run up from the front of the car(X-Man provided a diagram for this not long ago showing what wire needs to be tapped and run to the new fuel pump relay in the back for this.) While you are doing this, redo the fuel pump ground wire to a 10 or 8awg and attach it to a good ground location in the trunk, you can even use the battery ground at this point. Once this is done the factory fuel pump resistor and relay assembly on the passenger fenderwell under the hood can be removed cleaning things up a bit. Tuck the free connectors under the abs unit the best you can.
The next wire you should run back is from your alternator main hot all the way back to your positive battery lug(Only do this if you run a master disconnect switch, explained below)
I also take this opportunity to install a master disconnect switch so everything is NHRA legal for when I go drag racing(Assuming your box is NHRA legal too, like the blue moroso one), so next up is to run from the positive battery lug to your master disconnect switch(If you aren't running the switch, run this wire from the + battery lug straight to the starter stud). The other side of the switch will run all the way up to the starter. If you don't run the alternator wire back to the + on the battery, the car wont shut when you flip the master disconnect switch. It will run off the alternator, even though there is no battery + in the system. Like I said above, you only need the alternator wire if you run the disconnect switch.
Here is where I get tricky. Since you no longer have a battery up front you have this terminal end that was used to connect to your battery +. I cut this terminal end off. What you are left with is what used to be the main feed for the starter and the feed for the power distribution block. Attach these two wires together. Now hook up your main stock starter wire terminal end (the one that goes on the stud using a nut) to the starter as it was stock and also attach the terminal end I said to attach to the starter earlier to the starter that goes back to the master disconnect switch. What you have done is you have power running through the switch, up to the starter and ends at the power distribution block and you also have no more loose ends.
****One thing I should add at this point is if you found your original starter wire to be corroding after you cut the battery + terminal end off, don't use that wire, make your own that will go from the power distribution block feed to the starter stud that will be nutted down with the other wire from the master disconnect in the back.****
Be sure to use a real heavy gauge for the wires going from the positive lug, through the master disconnect switch to the starter as that is what draws a ton. The power distribution block is using the old starter wire(unless you had to replace the wire because yours was corroding. I would use 6awg or thicker if this step is needed) so that wire should be fine and the wire for the alternator I wouldnt go any smaller then 6awg. I run an 8awg for my fuel pump and another 8awg for my MSD which both comes off my + battery lug. I recommend getting one of those gold plated positive terminal ends for big car stereos for your battery so you can run a few large and small gauge wires off your postive battery lug and everything stays nice and clean looking. I got mine at autozone. You also need to fuse or breaker everything properly. Also don't forget to run a vent tube from the box to outside of the cabin.
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