You should be able to create a standalone harnless with a new fuse box set up. I usually use a Painless 7 circuit Aux Fuse setup. That usually is enoough for a basic setup. If you need more circuits, the setup is expandable by adding another 4 circuit block on.
I then setup a another fuse and relay setup for the Elecrtical Fan if your using them. http://www.summitracing.com/parts/PRF-70207/ http://www.summitracing.com/parts/PRF-30002/
see my project post #98 and #100 for what I did.. 1971 Nova Swap - 02 LS1/A4
If your not good with wiring and can not find anyone local to help, you can look up one of the sponsor vendors to convert your factory harnless or buy a new custom one. But it is a good thing to learn about the EFI and wiring, it usually takes a few hours for the 1st timers, just need to read the FAQ and get the pin out of your year/model harness.
71' Chevelle, 99 LS1/Viper T56,Full Hotchkis TVS,Custom Cowl Induction CAI
84' Z-28 350/T5
88' C4 Coupe L98/A4 71' Nova - LS1/4L60E
, Full Hotchkis TVS Suspension
79' G-30 SWB 4X4 Van, 400cid / TH350 NP205
48' Ford F-1 1/2 Ton Truck, Stock 6cyc/3sp