I have in fact done the swap to an EFI 460in a 78 Bronco. I did some basic research and found that the very best donor vehicle for this swap is a van. the Vans come with the rear sump oil pan, high output large case alternators, and Saginaw PS pumps. I used 390 motor mounts and the motor dropped right into the factory frame perches, no modification at all needed. new 390 mounts were about $11 each, or you can buy a set of aftermarket ones for $100 US, your choice . There are a lot of extra tasks to the conversion such as the fuel system plumbing, hooking up kickdown linkages, adapting AC compresssor to work, modifying cruise control linkage etc. but all are managable. My EFI 460 Bronco has all working accesories AC , Cruise et al. my Carbed 460 in my 79 does make more power, but its a crude power, the EFI comes on very smoothly, and if you want to add just a touch more power you can, its very responsive, which more than makes up for gross power IMO. The 400 in my other 78 is still a decent power plant for DD use, its pretty bullet proof and starts well in any weather. There is no point in even trying to compare power output of a 460 to a 400 though, the 460 (carbed or EFI ) will whoop a 400 any time. I pulled a good 400 out of my now EFI Bronco and sold it for more than I paid for the donor van.