BerniesVette

I have had several PM's asking for this information and past threads can't be found so I thought I would post my swap one more time. This conversion cost me less than $1,500.00 and was the very best thing I did to my 79 auto tranny car. This parts I used are: 91 Mustang World Class T5 tranny. I bought mine locally from a mustang salvage yard and the cost was $550.00; Performance Parts & Sales New Market, TN, 865-484-1944; good people to work with. Be sure to buy the yoke with the tranny as it will be sold separately and the T5 yoke takes the same U-joints as the C3. I bought a chevy bellhousing from a salvage yard from a heavy duty chevy truck that had the slave bracket molded as part of the bellhousing, $75.00. A regular chevy bellhousing will work but you will have to fab a slave cylinder bracket; not hard to do. I bought a used flywheel for $50.00 (11" 153 teeth) and took it to a local clutch shop where they surfaced the flywheel and put together a kit that consisted of a chevy pressure plate, T5 clutch disc and alignment tool, T5 throwout bearing and both a chevy and ford pilot bushing. $225.00. I used the chevy pilot bushing and had a machine shop mill the inside diameter to match the T5 input shaft diameter. I bought a manual clutch and brake pedal and bracket set from a vendor at a Vette show for $75.00. I bought a master cylinder and slave cylinder for an 85 one ton chevy truck from a NAPA store along with an 18 inch steel brake tube and fittings to adapt the brake line to the cylinders. Approx. $100.00. I wrapped the brake tube around a coffee can so that the flex in the drivetrain would be absorbed by the circle created. A braided high pressure hose was much more expensive to accomplish the same result. I bought a hydraulic resevoir from a salvage yard that fit a Honda Civic for $5.00 and worked perfectly. You will have to shorten and balance the driveshaft a few inches and a local shop should do this for approx. $35.00. Now is a good time to replace those u-joints too. To adapt the tranny to the bellhousing I got an 11 inch square piece of 1/2 inch aluminum. I used 1/2 inch thick aluminum because the T5 input shaft is 1/2 inch longer than the chevy input shaft. I bought a chrome shifter used from a swap meet that works perfectly ($5.00). The T5 shifter works too. I did have to fab a bracket to move the shifter to the left one inch and back 1 1/2 inches to fit the original shifter location in the C3. You will need an adapter to adapt the speedo cable to the T5. I got mine from D & D Performance 248-735-6220 or www.ddperformance.com I think the price was approx $60.00. To get a listing for the specs on mustang T5 trannys go to www.fordmuscle.com to find a listing of transmission Id numbers with ratios and torque limits. I used one with a 3:35 first gear and a .68 overdrive ratio and it is great for acceleration and cruising.
The aluminum adapter plate will need to be milled. I took my plate and marked a line thru the plate vertically on it's center axis. Next come down that line 3 1/4 inches and mark a horizontal line. Where the lines intersect mill a hole 4.905 inches. This is to mate the T5 to the adapter. It is a snug fit and this is good. The center point for this hole is also the reference point for the next three holes you need to drill to mate the adapter to the bellhousing. First measure left from the center point 4.2435 inches and up 2.0015 inches, this hole is the only hole that needs to be counter sunk. Again measure from the center point left 4.1210 inches and down 2.8750 inches for the bottom left hole. Now, from the center point measure right 4.1255 inches and up
1.9770 inches for the top right hole. Thes are the only three holes needed to attach the adapter plate to the bellhousing and I believe I drilled 7/16th holes for these bolts. I used studs to mount the tranny to the adapter plate. The tranny should be tilted approx 15 degrees to the left and here is how you find where to mark the adapter plate for the four stud locations. Sit the T5 tranny on a workbench and place a short piece for 4 x 4 post under the rear tranny bracket. This will tilt the tranny left at the proper angle. Next place the adapter plate onto the front of the tranny snuggly against the tranny. Take a small level and place it on top of the adapter and rotate it until it is level. Clamp the adapter to the tranny and mark the 4 mounting hole locations on the adapter. This will properly mate the tranny to the to the bellhousing at the proper angle and allow the rear support to be flat to the mounting surface of the rear tranny support crossmember. I bought a T5 rubber tranny support from Autozone to mate the tranny to the cross member support. This information was provided to me by Norval Wilhelm and Carguy4sure (Doug) who had done this swap before me. For those of you weho are interested in this swap, I can walk you thru the process as you go if you need additional help. This is the greatest mod you can do to your C3!
Bernie

sly vette

Thank you very much Bernie!!!

Durango_Boy

GREAT writeup. Saves a lot of time for all the guys who are gonna PM you for the above information.

I would like to offer my services to anyone who needs help finding those parts. I can order the bell housings, master and slave cylinders, and transmissions...all used from salvage yards in your area to save on shipping. Just PM me what you need and I'll do what I can to save you money on used parts.

BerniesVette

Thanks guys! A couple things I forgot to mention. You will need to buy an adjustable clutch fork pivot stud to make sure you get the clutch travel you need. Secondly, you will probably have to cut off some of the throwout bearing retainer on the Tranny. Mine was too long and would not let the throwout bearing release the clutch disc. The bearing retainer was too long and pushed the clutch fingers in until there was no room to release the clutch. You must measure the length of the retainer and the distance to the clutch fingers from the bellhousing and cut the retainer with a cutoff wheel so that it has approx 1/4 inch of distance from the clutch fingers when installed. Just enough to allow the throwout bearing to engage the fingers without coming off the end of the bearing retainer. Also make sure the throwout bearing can swivel on the clutch fork without any binding. I had to grind just a little off the clutch fork ears to let the bearing swivel freely on the fork. Hope this doesn't sound too complicated because it isn't and is a really fun project to do.
Bernie

Durango_Boy

Hey Bernie...do you have any pics for the install to add to the thread? You know how much we love pics.

BerniesVette

Here are some pics:

























The yoke you see on the tranny is the wrong yoke. It is for a 4 or 6 cylinder engine. Be sure you do not get one of those. I got this one by mistake. I hope the pics help.
Bernie

Durango_Boy

Thanks Bernie...those helped a lot. A visual always helps when getting into a project like these.

BerniesVette

As you guys start your swaps let us know if you need any help. We can walk you thru anything that might pose a problem! Norval and Doug were lifesavers to me when I did mine. Check out the adapter between my bellhousing and tranny. That is how you want to trim the edges after you get the holes located and drilled into it. You have to look really hard to even realize ther is an adapter there.
Bernie

Restorod '79

Thanks Bernie- I just printed out my shopping list. It'll be a while before I start, but your thread has given me courage!

Durango_Boy

Who's Doug?

sly vette

Thank you again Bernie.

BerniesVette

It is my pleasure to help anyone with a mod to make their car better. I received a lot of help from Norval and Doug (Carguy4sure) when I did mine, so the least I can do is keep the tradition of helping alive! Let us know if you have any questions or concerns; I sure did!
Bernie

norvalwilhelm

This is a the adapter plate. Later you trim the outside for looks
This is the rough plate and the location of the large hole
Do NOT NOT drill the upper right hand hole unless you are using a 94 or newer T5
Th plate is 1/2 inch thick

This is the addresses of some of the other holes. Center on the large hole and then go to these addresses and drill the mounting holes.

BerniesVette

Norval,
Thanks for posting pics of the adapter plate! I was going to do it today as I have it stored on my company computer. This will help all those who are wanting to do this swap! Thanks again for all your help. You are indespensable to this forum.
Bernie

norvalwilhelm

Guys if any of you actually get to the point of getting the T5 and making this plate we can go on from here.
Bernie or I can talk you through the rest of the mounting but most never get here.

Durango_Boy

Why is that? They give up or find a better project?

I know I will be there for sure but I will be putting all this together for a Vette I don't even have yet.

adam

Great writeup bernie.


Did you have to pay extra for the yoke, or did you ask and they throw it in?

How much was the rubber tranny support ?

Do you have a picture of the bracket you fabbed for the shifter?

Lastly, what are the desirable specs for a tranny? I've seen the first gear go from 2.93? to 3.35.

Thanks.

BerniesVette

Adam,
The T5 I used had the 3:35 1st gear. It works great with the 3:55 rear gears. Also it had the highest torque rating. I bought a T5 rubber tranny support from auto zone for approx $10.00.
Bernie

Travis Johnson

Where do you get that info from? I usually use www.car-part.com, any other good ones around?

Durango_Boy

They are very similar to Car-parts.com, but I'm actually not supposed to know about this network, so I can't divulge the info. I can just help find the parts and pass along that info.