I have that exact engine in my bronco right now.....I swapped the old 400m carburated out for the 460 EFI..........I also called painless wiring and they told me to send them both wiring harnesses from BOTH trucks and they could build me one........said it would be around 3000(plus whatever I had to pay for the harness) So there was no way i could do that plus I only had my harness at the time...... After doing so research I found it would be easier to build my own so I found another truck with the harness still intack and computer/sensors.......it cost me about 600.....I spent about 15 hours cutting and splicing.......I spent most of my time on the ignition switch with wiring diagrams covering the entire work bench! I was able to get it all working and it actually fired right up once I got the right fireing order worked out!
In the end I would have gone with a totally different engine.........Love the power but it weighs around 650LBS and it was a nightmare to put in....
if you have any more ??? feel free to ask......