Ok, I've decided I'm going to put in an efi v6 into my 78 ghia, I plan on using an engine from a 94 or 95 mustang. I would like to take out the three speed automatic and put in a four speed automatic and was wondering what kind of modifications would be needed. I'd also like to put disc brakes on the back but haven't seen any conversion kits for that year mustang, would I be better off putting in a newer rear axle and if so does anyone have a recommendation. Thanks for the help.
putting in the EFI v6 from a 94-95 Mustang is going to put you in uncharted waters. The 3.8L V6 used in Mustangs from 1994-2004 was never used in our cars, so there are no existing mounts for the swap. The AODE transmission used behind them is straightforward enough, but complicated (you've got to modify several things to get one to fit) and there are no manifolds available that are a direct fit for this swap.
If you want an EFI V6, your better bet would be from the 2.9/3.0/4.0 family of engines that was used in the Bronco II, Aerostar, Ranger, and Explorer. These are all continuations on the 2.8L V6 originally used in the Mustang II up to and including the current 4.0SOHC available in the Ranger, Explorer, and Mustang (2005+) Anything you do with the 1996 and newer engines is more complicated to to their OBD-II computers and more involved wiring harnesses, but the 1995 and older V6s all use the EEC-IV based system that is more easily swapped due to the smaller number of functions controlled. 1992 and older systems are in general even easier to use still due to airbags being optional (make sure you get your computer, engine, transmission and harness from the same car for the best results) so you don't have the extra wires to worry about.
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1976 Ford Mustang II Ghia: 302 with a 600cfm Edelbrock carb, Edelbrock Performer 289 intake, Dynomax Blackjack headers, 2.5" exhaust with Flowmaster Super 44s. RJS 11-gallon fuel cell, C4 tranny, chrome 16" pony wheels, fuzzy dice, brown vinyl half-top, and painted in the tackiest color ever (harvest gold, that's why I call it "The Goldenrod").
Also have a 2003 Dodge Ram (lightly modded daily driver/tow rig/office/dining room/home away from home/workshop... I call it "The Big Blue Dawg".)
honestly, if durability and/or fitment are a concern? I would stick with what you've got. None of Ford's automatic overdrives are particularly noted for their durability.
The familys of four-speed automatic overdrives include the following:
AOD
AOD-E
4R70W (by far the most durable, but not likely to easily fit in a II or bolt up to a V6)
A4LD (by far the worst, a stock 88hp 2.3L engine can shred one like tissue paper.)
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1976 Ford Mustang II Ghia: 302 with a 600cfm Edelbrock carb, Edelbrock Performer 289 intake, Dynomax Blackjack headers, 2.5" exhaust with Flowmaster Super 44s. RJS 11-gallon fuel cell, C4 tranny, chrome 16" pony wheels, fuzzy dice, brown vinyl half-top, and painted in the tackiest color ever (harvest gold, that's why I call it "The Goldenrod").
Also have a 2003 Dodge Ram (lightly modded daily driver/tow rig/office/dining room/home away from home/workshop... I call it "The Big Blue Dawg".)
ok, what about going with a manual tranny? I know I'd need to get the pedals and linkage for it, would I have any problems fitting it to any of the engines you mentioned above?
You'd just have to get a 5spd from a 2.8/2.9/3.0/4.0 Ranger, then put the Mustang II 2.8 bellhousing on it.
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1976 Ford Mustang II Ghia: 302 with a 600cfm Edelbrock carb, Edelbrock Performer 289 intake, Dynomax Blackjack headers, 2.5" exhaust with Flowmaster Super 44s. RJS 11-gallon fuel cell, C4 tranny, chrome 16" pony wheels, fuzzy dice, brown vinyl half-top, and painted in the tackiest color ever (harvest gold, that's why I call it "The Goldenrod").
Also have a 2003 Dodge Ram (lightly modded daily driver/tow rig/office/dining room/home away from home/workshop... I call it "The Big Blue Dawg".)
1994-1995 Mustang Engine... 
