'68 Cougar upgrade to a 6 speed (6R80) Auto

[Gaugster]

I've made big plans for the Cougar this winter. The C6 three speed started slipping badly and I hear very good things about the 6R80. Long term plan is for my 390 engine to have a substantial power increase. Like 2X or 3X over stock. So beefing up the powertrain etc...makes a lot of sense. Here's some progress.

I have had to make clearance in the tunnel. No cutting yet but anticipate that I will need to make two small holes in the firewall so that I can torque the top transmission to block bolts. As some of you know I participate in the Classic Cougar forum. I have a post going over there too and will try to keep them both updated. This thread focused more on the FE whereas the Cougar forum gets more of the vehicle attention.

https://rumble.com/vbseqb-6r80-automatic-retrofit-1968-mercury-cougar-390-fe-big-block-p3.html

I am using the Speed Gems adaptor kit and so far the fit and finish have been great. The new starter has an integrated solenoid. I kept the original Ford solenoid mounted on the fender well. I'm not confident of the Cougar's 12V solenoid feed to have enough current to power the new solenoid+bendix. So I ran a dedicated 4 AWG battery cable to the starter and beefed up the ground return also. Now the original Ford solenoid output switches 12V to the new solenoid downstream. The new solenoid wire is 10 AWG. Overkill perhaps but it's what I had on hand. I will use a heat shield wrap over the starter. Doing everything I can think of to avoid the possibility of a heat-soaked starter lag issue.

The goal for today will be to confirm that starter works and can crank the engine. I have read about starters bending flex plates without the torque converter installed. So my plan is to bolt up the converter before putting any load on the flex plate.

[gregaba]

Good information. I used headers on mine and had more clearance then you have, I also used the fender mounted solenoid mainly because I am a old time mechanic and I like being able to hook up my remote starter switch instead of crawling under the car to hook it up to the solenoid.
Greg

[Gaugster]

Thanks. I have been reading the header posts in the Technical section. When under my car I was laughing at the thought of using a set in my Cougar with full shock towers. That's a problem for another day/year...

[Towd56]

What controller are you using with the 6r80?

[Gaugster]

What controller are you using with the 6r80?

I'm using the Quick 6 from US shift. Also got a Holley TPS kit to add to my Quick Fuel carburetor. The Holley and QF aren't exactly the same but I'm told it will work.

[Towd56]

What controller are you using with the 6r80?

I'm using the Quick 6 from US shift. Also got a Holley TPS kit to add to my Quick Fuel carburetor. The Holley and QF aren't exactly the same but I'm told it will work.

I just checked their website. Unbelievable what that controller can do.

[Rory428]

I am not an automatic guy, but thats quite interesting. What do you do for making the speedometer function? I imagine that you will need a driveshaft with a slip spline in the shaft. I have seen newer vehicle that some have that in the front section, others in the rear. Not sure if that matters one way of the other, just curious. Do these  have transmision dipsticks, or are they closed transmissions that require special procedures to check & add ATF to?

[e philpott]

Rory the ones I've seen have the a little dip stick right by the pan , no long tube anymore

Lockup is strong so you can program lockup at the end of each gear and it will feel like a 11 speed transmission with lockup in 2nd gear on up

[Gaugster]

I have done detailed research on most of the aspects of this swap. Plenty of things can go right or wrong but that's part of the fun.

A few companies make electrical input to cable output for driving mechanical speedometers. Dakota Digital has a device that I will probably use. Jegs and Summit list other options. I have a $700 budget for a custom aluminum driveshaft. But I hear rumors about some Ford's ('06 Explorers?) having an aluminum one. Most have the slip spline in the middle vs a slip yoke at the end. Guessing the lengths are some common denominator between the 2WD and 4WD systems. This and the trans mount are the biggest unknowns currently. Several companies make mounts into fox body and early model Mustangs. Will check if I can modify one somehow.
 
The 6R80 uses Mercron LV fluid which is intended for extended service intervals. As stated a mini dipstick with a specific checking procedure.

Lokar makes a sport shifter that is more hot rod style.

6 speeds with a lock up converter will make for a fun ride!

[Gaugster]

Test of the starter and wiring went well. Next step is to mount up the transmission, perform all the wiring of the new ECU and devise a mount for the tail shaft end.

https://rumble.com/vbupqp-6r80-automatic-retrofit-1968-mercury-cougar-390-fe-big-block-p4.html

[BigBlueIron]

I would love to do this swap one day. Thanks for the write up.

Is that cam plug in backwards??

[Gaugster]

I would love to do this swap one day. Thanks for the write up.

Is that cam plug in backwards??

Good catch on the cam plug. Yup. It's backward. Been that way for 20 years as far as I know. Hoping I can get another couple seasons out of the motor before I redo it.

I am excited to see how the 6R80 works. Still reshaping the tunnel to fit everything. Looks like I will only need one small additional hole in order to tighten the bellhousing bolts.

[BigBlueIron]

I figured it had been that way for quite some time, obviously it hasn't caused an issue.

[TomP]

I am curious why that adapter plate is that thick? It would seem like it could be half that thickness and at least give a chance to clear the firewall in most cars.
 I'm surprised the six speeds go for that much, there must be lots out there by now. There was a ten speed from a 2018 Mustang on local Craigslist for less than what some are asking for a 50,000 mile six speed.

[Gaugster]

I am curious why that adapter plate is that thick? It would seem like it could be half that thickness and at least give a chance to clear the firewall in most cars.
 I'm surprised the six speeds go for that much, there must be lots out there by now. There was a ten speed from a 2018 Mustang on local Craigslist for less than what some are asking for a 50,000 mile six speed.

At 1.5" it seems to be one of the thinner options. I think it was a comment on the Cougar forum but another kit for SBF was pushing 3". The crank adaptor itself is 1 inch thick. Add the new flywheel with enough room for a starter gear throw and your at 1.5" with ease.

They don't have an aftermarket controller for the 10 speed yet but I've read that it's in the works. Cost of the salvage  F-150 6r80 is anywhere from 300 to 1000 based on mileage. Double that if its from a Mustang but for no real reason.

[Gaugster]

Achieved a milestone today. After a bunch of rework to the tunnel and a little trimming of the transmission housing I was able to get the bell housing to sit on the adaptor dowel pins. Somewhat regrettably I had to make one access hole in the firewall for the passenger side top bell housing bolt. Aside from pulling the engine I couldn't think of any other option. It will be torqued to specification at least. More room on the driver's side which should allow for top side bolt access with the right wrench.

https://rumble.com/vc5u7n-6r80-automatic-retrofit-1968-mercury-cougar-390-fe-big-block-p5.html?mref=23gga&mrefc=8

https://rumble.com/vc5u3h-6r80-automatic-retrofit-1968-mercury-cougar-390-fe-big-block-p6.html?mref=23gga&mrefc=8

Here's some of the "carnage" to the firewall, tunnel and original cross member. Once I determine the pitch of the engine/transmission, u-joints pinion angle etc... I will know if more clearance and/or vibration isolation is needed.

[driveamerican]

When doing this type of conversion now do you check block to adapter alignment for center on the crank?

[Gaugster]

When doing this type of conversion now do you check block to adapter alignment for center on the crank?

The adapter that I purchased uses the blocks original alignment dowels. It's a tight fit and I just have to trust the quality of the kit. What I can control is the mating surfaces and I have wire brushed them down to be clean, rust and paint free.

[driveamerican]

Thanks I have done flywheel housings for trucks and once you do it the process isnt bad, at the same time I have never had a reason to check on a gas engine. So I was curious, I would think if you didn't have problems with the c6 you won't have trouble with the adapter. Good luck.

[Gaugster]

I worked out the design of the fluid cooling system. Very happy with the initial results. I made a mounting plate that replaces the factory splash shield. Need to finalize the 8AN hose routing and prepare some form of shield to protect it from road debris etc... I did a "candle test" and didn't burn the house down. 

Updated 2/5/21 - Added picture of the debris shield I am going to use. My local Lowes has leaf guards made of metal and painted black. Cut them into two sections and zip tied. A Keep It Simple Stupid (KISS) moment for sure.

https://rumble.com/vcjs83-6r80-automatic-retrofit-1968-mercury-cougar-390-fe-big-block-p7.html

[Gaugster]

In the past couple weeks I was able to finalize the installation of the 6 speed onto the 390. A solid "three clicks" to seat the torque converter. Also did the lion's share of the electrical in the engine bay. Next step will be the X-Member installation and benchmarking my engine angle options. Just a quick plug - I have had some in depth conversations with the people over at Stiffler's, Lokar and Power By the Hour. All of them have been awesome in support of my quest.

Here's the videos....

https://rumble.com/vcyvhl-6r80-automatic-retrofit-1968-mercury-cougar-390-fe-big-block-p8.html
https://rumble.com/vcyvn5-6r80-automatic-retrofit-1968-mercury-cougar-390-fe-big-block-p9.html
https://rumble.com/vcyvoj-6r80-automatic-retrofit-1968-mercury-cougar-390-fe-big-block-p10.html

[XxSlowpokexX]

Awesome. Going through this process on one of my other cars.  I was also really wanting to do the ten speed swap on that but no controller just yet.  I also just picked up a 64 galaxy with a 390 and this would be a great option in the future.  I don't however really want to be banging away at the trans tunnel though.  This is going to be night and day over that C6

[Gaugster]

Thanks for the complements. Yup, a little more metal work that I was hoping for but the end result will make it all worth it.

[Gaugster]

The transmission upgrade has been going well. It was a true pleasure to install the Stiffler's cross member. Up to now most of the work required considerable fabrication/trials but this puppy just bolted right in place. I can achieve between 2° - 4° of rearward engine slope. This should be fine but I won't know for sure until I source the drive shaft. It was a minor miracle that my exhaust cleared as is. Now I have been getting familiar with the Quick 6 controller and evaluating the throttle linkage/TPS setup. I am waiting for the Lokar Sport shifter and some cooling line fittings from PBH. Those should start showing up in the next couple of weeks. I think I have come up with a real slick way of mounting the Quick 6. It should be bitchin! Here's a video with some more detail on the TPS install.

https://rumble.com/vdgmkl-6r80-automatic-retrofit-1968-mercury-cougar-390-fe-big-block-p11.html

[Joey120373]

Great work! I will be following this project.

Hopefully, if a still have a job in the next few years, I will be putting a 6R80 in my 72 F250.
For now it’s motor first, then trans.

But the thought occurred to me a while back that just popping in a 6R80 behind the lackluster 360 that’s in it now would completely transform how the truck drives. That low first gear would really wake it up.

[Gaugster]

Great work! I will be following this project.

Hopefully, if a still have a job in the next few years, I will be putting a 6R80 in my 72 F250.
For now it’s motor first, then trans.

But the thought occurred to me a while back that just popping in a 6R80 behind the lackluster 360 that’s in it now would completely transform how the truck drives. That low first gear would really wake it up.

Thanks and good luck with your motor build! Yes I am hoping to greatly improved the drivability. My C6 failed so I went down this path. I am between jobs currently so this has kept me busy. I'll need two jobs for the motor I want to build.

[Joey120373]

I have been looking at used 6R89s, there appear to be 2 different bell housings.

Looking at your pics, I am assuming that you have to use a trans that came behind a 5.0 and not an eco-boost ? Looks to me like the top two bell housing bolts are spread farther apart on the v8 case.

Just wanted to verify before I bought a trans.

[Gaugster]

I have been looking at used 6R89s, there appear to be 2 different bell housings.

Looking at your pics, I am assuming that you have to use a trans that came behind a 5.0 and not an eco-boost ? Looks to me like the top two bell housing bolts are spread farther apart on the v8 case.

Just wanted to verify before I bought a trans.

That's correct. All the adaptors and supporting hardware/software are specific to the V8, 5.0L 6R80's. 2WD is ideal for car applications. 4WD trans could be used but the output shaft will need to be converted. Here's some info to help hone your search. 2011–2017 are the years to purchase from a Mustang or F-150/Expedition etc... 2015–2017 F-150 6R80's use an external cooler bypass. Best to avoid this if possible OR install the internal thermostatic bypass. IMO

[TimeWarpF100]

I have been looking at used 6R89s, there appear to be 2 different bell housings.

Looking at your pics, I am assuming that you have to use a trans that came behind a 5.0 and not an eco-boost ? Looks to me like the top two bell housing bolts are spread farther apart on the v8 case.

Just wanted to verify before I bought a trans.

That's correct. All the adaptors and supporting hardware/software are specific to the V8, 5.0L 6R80's. 2WD is ideal for car applications. 4WD trans could be used but the output shaft will need to be converted. Here's some info to help hone your search. 2011–2017 are the years to purchase from a Mustang or F-150/Expedition etc... 2015–2017 F-150 6R80's use an external cooler bypass. Best to avoid this if possible OR install the internal thermostatic bypass. IMO

I really like the 6R80 & installed them in 3 of my '66 Trucks (non fe) Now decided to try the 10R80 in current swap again non FE. The 10R80 is a monster and gotta be more than 2x the weight of the C6 and in height it is very tall. Got it to fit in the '66 short bed but quite close. Cant wait to try it out.

[Gaugster]

I have been looking at used 6R89s, there appear to be 2 different bell housings.

Looking at your pics, I am assuming that you have to use a trans that came behind a 5.0 and not an eco-boost ? Looks to me like the top two bell housing bolts are spread farther apart on the v8 case.

Just wanted to verify before I bought a trans.

That's correct. All the adaptors and supporting hardware/software are specific to the V8, 5.0L 6R80's. 2WD is ideal for car applications. 4WD trans could be used but the output shaft will need to be converted. Here's some info to help hone your search. 2011–2017 are the years to purchase from a Mustang or F-150/Expedition etc... 2015–2017 F-150 6R80's use an external cooler bypass. Best to avoid this if possible OR install the internal thermostatic bypass. IMO

I really like the 6R80 & installed them in 3 of my '66 Trucks (non fe) Now decided to try the 10R80 in current swap again non FE. The 10R80 is a monster and gotta be more than 2x the weight of the C6 and in height it is very tall. Got it to fit in the '66 short bed but quite close. Cant wait to try it out.

How's the aftermarket for the 10R80? I know that US Shift has been working on developing a controller for it. Personally I haven't checked about OEM computers since you typically need to a modern trans and engine. What to the shifter options for the 10 speed look like?

[Gaugster]

Just a quick video update. Still waiting for the custom shifter but I rigged up the old one so that I could start and cycle the gears and fill the transmission with fluid.

https://rumble.com/vf2ufn-6r80-automatic-retrofit-1968-mercury-cougar-390-fe-big-block-p12.html

[67xr7cat]

Sounds good!

[Gaugster]

Doing my first official test drive tomorrow. To date this transmission modification has been a roaring success. Aside from a small fuel leak I haven't had any issues in the first 100 miles. The motor/6R80 combo works well together. I am using a regular Lokar Sport Shifter as I wait for the custom stick to show up.

[Gaugster]

Test.

[jayb]

test

[Gaugster]

Update showing the real shifter.