Need a rare 2.3 c-4 bellhousing or 2.0 c-4 bellhousing. t-5 driveshaft will work. Here is writeup.
am running a c-4 behind my 2.3 turbo. This is my experience on installing a c-4 behind my 2.3 turbo in a 89 Mustang. Some of this is basic info all know. But since putting in FAQ thought I would mention all of it.
Going from A4ld to c-4. First A4LD bellhousing is useless and so is driveshaft. C-3 Bellhousing is not useful either.
The sheet metal plate between motor and
trans can be reused. I took this plate with me to find the 2 transmission I found that had the proper bellhousing. I just laid against the bellhousing to confirm fit.
Flexplate need to be a c-4 one from a Pinto. Around the years of 1974 to 78 not sure on years.
Bellhousing will carry a casting number of D42F7976AA. Also from those years. This can be a hard to find expensive things. Hint look at old pile of
trans unlabeled in old junk buses. This is how I found one of mine.
http://mmerlinn.bravehost.com/trans/fdc4f/fd6c4bhm.htm http://mmerlinn.bravehost.com/pics/fdc4f/f71pc4f.htm
There is a c-4 2.0 bellhousing unsure of part number with that will need stepdown dowels. Do a search here, there is someone here that makes them. Remember reading in a post. Stinger has a adapter plate to use a 5.0 bellhousing. Contact him for more info.
http://www.stinger-performance.com/suspensionparts.html
On the torque convertor I am using a stock stall Pinto convertor. Some with more HP are using custom stall ones. This varies from what I read according to when turbo spools up. So can not give advice on it.
The proper c-4 is a case fill c-4.
Rear
trans mount is stock c-4 for a Mustang. Your crossmember will work.
The vac line from the A4LD will work and hook up to the modulator on the c-4
The A4LD
trans lines will work. One of them will need to be extended about 1 foot. Flush the lines. If using rubber lines make sure rated for hi-pressure. I used steel line.
Speedometer will fit the
trans.
Your A4ld shifter will not work. It is not gated properly. Will need a c-4 shifter from early Mustang with c-4 or Pinto. Can modify it to fit console on later Mustangs. I removed the upper indicator. Ground mounts off and dismantle indicator removed the OD symbol. And lined up and mounted with self starting screws to the c-4 shifter.
http://i177.photobucket.com/albums/w224/mgman75/100_6180.jpg Notice OD section is gone.
Or can order performance type c-4 shifter.
Kiddown on the shifter. Since c-4 was never behind a EFI 2.3. None is available. I took a A4LD cable and modified to fit the c-4 but never installed. Mine downshifts without it so I never installed.
The driveshaft. I used a Ford Motorsport driveshaft for a t-5-c-4. Or can use a t-5 driveshaft.
On wiring there is 2 plugs on the A4LD. A round one and another. The 2 wire one is not used and can be tied out of the way. The round plug has the wiring for the neutral switch and backup lights. Will need the wiring diagram for your car and for the c-4 switch to fiqure out. I will look for how I fiqured it out and post later.
Lastly you are now running a 3 speed instead of 4 speed
trans. RPM with the 373 gears in stock rearend with kill fuel economy. I install a 345 turbocoupe rearend that suits my applicatiion.
Since more than likely like me the
trans will not come with dipstick. I ordered a c-4 v-8 from Summit. Only one I could find. It is chrome. Mock into
trans and make a bracket to make it reach the
trans. It come with a clamp. When you got it where you want. Make sure have pressure on it so will stay in
trans. Weld or braze clamp to tube. Remove the chrome where it goes in
trans. Add a o-ring and some red silicone. The reason I mention this is it caused me alot grief. Tube would move and leak
trans fluid before I removed it and done this procedure. Since I have done this no problems.
Thanks Maurice
I know cut and paste but I am not rewriting this. Maurice
How much hp...? 
