Over the past year and a half, I've helped to develop an adaptor to bolt any small-block V8 GM transmission behind a small-block ford motor. This project stemmed from a desire to have an overdrive transmission in my 1973 Bronco. After many hours of research and debating between the AOD, AOD-EW/4R70W, and 700R4 , I chose the 700 for these reasons:

• Low first gear (3.06) compared to other Ford automatics:
  • C4 is 2.46:1
  • AOD is 2.40:1
  • AOD-EW/4R70W is 2.84:1
• Overdrive in the 700R4, .74:1, is more usable for large tires and street gearing (4.11-4.88:1) than the AOD/AOD-EW/4R70W (.67:1) . In the latter, you will need very deep gearing, smaller tires, or a very low torque/rpm band to take advantage of this deep overdrive (in essence, don't plan on having a stock 302, 35" tires, and 4.11's and being able to use it at less than 85 mph).
• The 700R4 has a readily available and cheap core, compared to the AOD-EW/4R70W:
  • Most yards want $5-700 for a AOD-EW/4R70W core, due to their more limited availability in a 302/351 bolt pattern
  • most yards want $1-200 for any 700 core
• The AOD-EW/4R70W needs a $300 aftermarket electronic control box to tell it when to shift, etc (http://www.baumannengineering.com/tcs.htm)
• To convert the TV-cable controlled AOD to the lower first gear of the AOD-EW/4R70W, you have to pay Ford Racing Performance Products $650 for a kit - and you're still not as low as a 700R4.
• I had a hard time finding any shops that specializied in building up AOD/AOD-EW/4R70W transmissions for performance applications - especially in my area. The 700R4 is one of the most common transmissions out there, and most competant shops offer performance rebuilds for this transmission.
• Upon it's release in 1982 the 700 was a mediocre transmission at best,. However, by 1987 GM resolved all of the transmission's problems, and all the internal components can be readily interchanged and upgraded.

A few companies have offered kits to adapt a SB Chevy transmisison behind a SB Ford engine, but none were truly bolt in:

• TCI's kit is basically a square plate - you're left to trim it, the starter won't bolt directly in, and you will need to have a crank/hub spacer machined. You will also need to provide the specifications for the hub adaptor to the machine shop yourself.
• Art-Carr's kit had even more problems - the plate was nicely fit and trimmed, but was made of soft aluminum. The crank hub to torque converter didn't fit at all (.500" off), and the torque converter to flexplate mounting consisted of 3 washer-type spacers, and a hand-drawn diagram of where to drill your flexplate (which won't work with most flexplates due to the holes falling on the "ramp" or incline). There were also problems with balancing this assembly

These situations, along with the frustration of putting in your motor 6 times, only to find out that it still won't mate to your transmission led to the development of the current kit:

• The adaptor plate is essentially the same as the Art-Carr unit, but machined from steel instead.
• The torque converter to flexplate adaptor is now a one-piece unit, machined from aluminum to keep the rotating mass lower.
• The dust cover is now included, as is all other installation hardware.
• The correct imbalance flexplate for your motor is also now included.
• Pictures below courtesy of Kevin Dill - THE engineer at Advance Adapters that made this adapter a reality for large scale production.