yo; Ask our good friend and 460 swap expert JSME84; 5.8 to 460 Swap in an 86
Source: by justshootme84 (Randy Z, Casual Mudder) at Ford Bronco Zone Forums
http://broncozone.com/forums/index.php?showtopic=7785
5.0 to 460 Swap in an 89
Source: by Steve D at ford.off-road.com
I put a 1994 EFI 460 and the E4OD transmission it came with in my 89 Bronco. The Bronco came with an EFI 302 with AOD transmission and BW 13-56 T-case. The motor was supposed to go into a 1994 F-350 but the chassis was pulled off the assembly line for a QA inspection. Since the engine and transmission were already together, and the next truck on the assembly line wasn't an F-350, they dropped the engine/transmission onto a pallet, shipped it to Leanard Vasholtz of Pikes Peak Hillclimb fame (he races Bronco's up Pikes Peak every July 4) and I bought it from him for $4k. I used my original BW 13-56 t-case because it was the t-case they were using behind that combo in 1994, and it was a bolt on. Never had a problem with it and it has been beat to death offroad, towing, etc...
Your best bet is to either find a complete donor vehicle from which to take all the parts out of, or check into your local FORD dealer and see if they have the EFI 460's for sale as a crate motor. I had to buy the ECM (460 computer), chassis wiring harness from a 1994 F-350 and splice it to the existing 1989 harness to get everything to work properly. The engine comes with a harness on it which includes all the wiring for the engine sensors. It connects to a weather tight plug that then connects the engine harness to the ECM. It's kind of modular. Same goes for the E4OD. It has a harness which is for the transmission and t-case sensors and it connects to a plug that then connects the transmission to the ECM. These can be seen if you look under the hood near the black plastic fuse box that sits on the wheel well on the drivers side.
To make everything easier, I also bought the FORD EFI manual, the HELM wiring Schematics for both the 1994 and 1989 model year light trucks, and the HELM service manuals for the 1994 Light Trucks. The wiring schematics have all the circuit ID's and color codes for both model years, and most of them match exactly. All I did was splice the 1994 underhood harness to the 1989 harness where it meets the firewall. It's a lot of work, believe me. Took me 2 days to drop in the motor and transmission and 7 weekends to wire it all...!
I used L&L motor mounts, custom fabricated the shift linkage for the E4OD because it is a cable operated shifter and my 89's was a bell crank style.
I had to fabricate a custom t-case mount support and cross member, and mounted the transmission to it also. I had to buy a 4 core Big Block radiator which was a bolt in, and added 2, B&M Transmission Coolers. I had to buy a remote oil filter kit from Transdapt because the stock filter hits the frame cross-member.
The 460 air cleaner mounts in the same exact location as a stock 91 would. I ended up buying a K&N Filtercharger kit and it mounts in the same place also. If you find that getting all the parts is too hard, you might seriously consider a late model 460, build it mildly and then run the Holley EFI system on it to gain the EFI advantages. IMHO, carbs went the way of the Dinosaur. I'll never own another carb'd truck again. I use mine more offroad than 90% of the 4WD's out there and EFI is the way to go hands down, end of story, period...
Keep in mind, the stock FORD EFI system on the 460 is Speed Density and it won't run on anything but a stock 460. You can get away with a K&N Filter, plugs, headers and plug wires, but just about any other mod to the engine i.e.: cam, heads, intake, etc. would cause the air flow into the engine to be out of the calculated ranges burnt into their PROM of the ECM, so it would attempt to run at the end of this scale and that's it... It might work, it might not...
If the system were the Mass Air type, typically found on Mustangs and the newer trucks, the engine can be modified and the ECM can handle it... If you are looking to run a cam, or anything other than pretty much box stock, go the Holley EFI route... It works, is simple to install compared to a FORD EFI system swap, and offers all the benefits of EFI without nearly the cost and aggravation...
see his eng compartmt. pic;
http://www.off-road.com/trucks4x4/data/articlestandard/ford/472005/198386/sdb7.jpg