5 Speed Conversion

We use the World Class T-5 on our GT350 resto's, and use the Mustangs Unlimited mounting kit which is about $400. Comes with crossmember and other assorted parts, but they're backordered on the kits last time I checked. It really is an easy swap, some minor modifications are needed to ensure a good fit, but it's very basic of a job. The T-5 is .63 OD. We use the TKO 600 for the Superformance Cobras and Daytonas with the .85 OD. The last Mustang we did had a 347 Stroker 400hp and the T-5 gearing was great with a 3:50 rear w/traction lok. When I finally get around to it, I plan on doing the 5spd conversion in my own 67 GT350 Shelby, that OD great is a must for cruising these days. I have my own source for the Tremecs, which are great products, no matter which one you use. The clutch linkage remains the same, but there is an adapter plate that has to be used which comes in that install kit.

 

Bill,

I put a new T5Z in my 66 about 4 months ago and have to say that it was the single best upgrade I have found for making the car fun for weekend drives again. I have a 3.89 rear (was 4.11) and the engine was screaming whenever I had to run down a highway (4-5k RPM). I may drop the rear ratio to 3.5 due to the close ratio of the trans gears.

I went with Modern Driveline -
http://www.moderndriveline.com/about.htm

I found it particularly helpful to have someone to go through the whole project with (I was also installing a 347 stroker). Bruce Couture is the owner and very knowledgeable. I also like his crossmember better than the California Pony Cars unit. I was keeping my Cobra scattershied and old Z-bar, so it was more of a mix and match situation than going with a completely new setup with cable clutch etc.

There's a good article on this (and several related topics) at Ford Muscle:
http://www.fordmuscle.com/archives/2000/09/t5swap/

I wish you luck in your research.

j

Jim Langendoen
6s1801
6s2021

 

I did it to my clone. I would have to echo the statement that it is the single best thing you can do to these cars to improve them... I used a T 5 and it is great. I have a steel bell housing and the adapter plate. Standard clutch linkage... The old speedo cable (from a T10) just went right into the hole in the new tranny.. The conversion was that nice. I have the regular 4 speed shifter attached to the T5.. You have to get under the car and look to see that it has been done.

Highly recommended!!!!
jimbo

 

The TKO / 3550 could require modifying the tranny tunnel in an early car. A t5 / t5-z will bolt in without having to modify any metal. I installed a T5-Z into my '70 Cougar with a JMC hydraulic clutch setup. With a hurst t-handle shifter, it looks very period correct.

 

Bill,
You may want to check out the G-Force gear set for a T5:

http://www.fordmuscle.com/archives/2005/12/T5Rebuild/index.php

Though, I think they actually lower the overdrive ratio which would work against you even more.

 

Bill,
I have the C7---"lemans" cam on my 289.. It is kind of old school bumpy.
(great sound with an X pipe!)..55 mph = 2000 rpm. It is perfect on the hi-way. If you want to get away from some rice rocket drop her down to 4...
.... But With 3.89 gears I wish my T5 had the first gear modification that made first gear faster.. It has this granny gear thing going on that is not quite right.... It is OK, but if I ever take the tranny out again it is going to be fixed...
Think about it,
jimbo

 

Bill,
Somebody out there has a cluster gear kit.. with all the parts to do it.... it changes the lower gears to more workable ratios..If you are looking for a good used T5 you wll probably need to go through it anyhow.. It is a nice tranny to work on.. I got the manual and had mine all apart. It was much easier to do than the parking brake, tail shaft, exhaust X pipe, confluence...
(the one square foot of hell under my car).
good luck with the swap ...you will love what it does to your car.
jimbo
also.. this is important.
There is a sleeve on the output shaft of the tranny that drives the nylon speedo gear. It has two ratios (I think one is seven turns and one is eight...)
One of them is impossible to get the corosponding nylon gear for so your speedometer is correct.. It is easy to change the sleeve when the tranny is on a bench.. durn near impossible when it is in the car.. Do the homework on this and save yourself some frustration...

 

Just for fun (I'm bored at work today ) I thought I would do a spreadsheet of the thrust curves for the toploader and the T5Z.

I have the gear ratios for the T5Z and the toploader (is it wide- or close-ratio for a '67 GT350?), but I can't find a reliable torque or power curve for the shelby-ized Hipo 289.

If anyone could point me to one that would be a big help.

Once done, I will try to share the spreadsheet (or at least a picture of the thrust curves) on this forum.

Thanks for any help you can give

 

Good point. Let me add to this, be sure to use a speedo gear clip for a T5. A toploader / C4 speedo gear clip will not keep the T5 speedo gear in place. This can result in the speedo gear coming loose (ask me how I know!). In my case, the speedo gear actually wedged against the drive gear and pushed it off the clip that holds it in place. This forced me to pull the tranny out and remove the tail shaft.

Good luck.

 

I put a T-5 in my 66 fastback with a 3.89 gear, If you are going to change the internal speedo gear put in a black 6 tooth from a 87 turbo coupe t-bird. This makes speedo correction even easier as you can use production cable gears form Fox body Mustangs. I bought my 6 tooth gear right from a Ford dealer just a few years ago, it was cheap then I also used a yellow 17 tooth gear on the cable. My speedo is right on accurate with my 17 inch tires.

 

Did the same to my 66 with also a 389 rear. My speedo is now 10 mph too fast with a 21 tooth driven gear and 225/60-14 rubber. Don't know what drive gear is on the tail shaft( 6,7, or 8) now but I think I need less teeth than I have now to slow the driven gear down, right?

 

There are charts & calculators on the Factory Five site to help figure this out:

http://www.ffcobra.com/FAQ/speedo.html

 

Hi guys

One questions to the Commissioner
What do you mean by:
some minor modifications are needed to ensure a good fit
And to the guys who drive the T5 with .63 O.D.
If you accelerate in 5th gear is it powerful or more or less dissapointing?
Please also tell me your rear end ratio.

Thanks Jerry

 

Hi Jerry,

I did a T-5 conversion about a year ago. The T-5 will fit the trans tunnel without mods. In my case I had to shorten the driveshaft, but I've heard that a lot of people don't need to. I've heard some people need to slightly modify the hole in the tunnel for the shifter to clear. I did not.

The TKO requires mods to the trans tunnel in a '65-'66 to acheive the correct drive train angle. There are cross members out there that will allow you to install a TKO without modification to the tunnel, but the result is a drivetrain angle that is outside the aceptable range.

With the T-5 there are a number of choices to adress with the bell housing/clutch setup (289/302 bellhousing/clutch linkage with a spacer between the tranny and bellhousing or 5.0 bellhousing and clutch). I went the route of using a 5.0 bellhousing and clutch so I'd get to use the bigger 10.5" clutch, which meant I had to find a 28 ounce imbalance flywheel drilled for a 10.5" clutch (the modern 5.0's are 50 ounce imbalance, the 289/302's used a 10" clutch) because the clutch release fork pivots on the opposite side of the bellhousing on a 5.0, I had to figure out how to make a clutch cable work. I didn't like the kits available, and wasn't happy with what I came up with, so I ended up using a hydraulic kit, which mounts a slave cylinder on the side of the trans to push the release fork from the tranny side (same as a cable pulling it). In the end, I was very happy with the hydraulic setup.

I run 3.89 gears in a 9". The acceleration is not great in 5th gear, but your engine will probably have a lot more punch than mine. Either way, I use 5th gear for highway cruising only.

You're not considering this for your R-model replica, are you?

Josh

 

Hi Josh

Thanks for the reply.
One question is still there.
Why do some have to modify the hole for the shifter and some not???
Every car and tranny s the same have you a answer to this?
And yes i want it for the replica. I know i know not original but you know
that germany is one big race track! ha ha ha And i need to go more that 160
with this car on open road without distroing my 12,5:1 engine at high rpm.

Hope you agree with me.
About the clutch i have to get back to you because on this subject
i´m still a greenhorn without any experience. And when i read balancing
flywheel and oz i just understand nothing anymore.
My engine is a 302 out of the 70tees.

What about alloy flywheels? Expensive but good??

Hope you can help
Bye Jerry


P.S. Here is how i modifyed my clutch pedal bracket
http://saacforum.com/index.php?topic=1762.0