Hey Andrew,

Can you do a compare with the 4r70w, 6r80, to the 8hp70?

I appreciate the chance to compare those transmissions, but frankly, I don;t know much about the 4r70 or the 6r80, except that they are older Ford transmissions. The 4r70 is similar to a GM 4L60 and the 6r80 is comparative to the GM 6L80.

The 4r70 is an older design and can be controlled directly with Holley EFI. The 6r80 cannon be controlled directly by Holley EFI, but I believe US Shift has a controller.

The 8HP is just an amazing transmission. I have been in the Chicago area the last couple of days. I am staying with my friend with the Fairlane and we will be heading to LS Fest tomorrow. Riding in the Fairlane is an unreal experience. The car can go from a lazy Sunday cruiser to a race car with a trans brake at the click of a switch. We ran across newer BMW M5 that wanted to play and I think he was a little surprised when we pulled on him, despite his "blurble" tune...

Andrew

Thats why I'm looking at doing either 8hp70 or 8hp90. After looking at size comparison you did of the 4l80e and t56 to the 8hp90 and 8hp70. I'm thinking of going with the 8hp90 for the peace of mind.

It will be interesting to see how the 8HP70 holds up in the two test vehicles that I am involved with. We will be racing both of them at LS Fest this weekend. The Fairlane has 700HP at the crank and the BMW made over 700RWHP.

The Fairlane will be launching off the trans brake with a 2-step rev limiter. That car has always hooked pretty well.

The BWM will be launched softer off a foot brake, mostly to keep the rear axles from breaking, although he has spares, just in case.

I too have been looking for a 8HP90 for my GTO, but the price and lack of availability might put me into an 8HP70.

Andrew

Will you be recording those races for you yt channel?

I'm hoping to get mine sorted out by March. Then emailing you tuning.

I'll definitely be taking as much video content as possible. If you have any questions, don't hesitate to email me: projectgattago at gmail dot com

Andrew

Awesome, thanks

Looking forward to those results. Very strongly considering this as a replacement to my 80e in the C10.

8hp70 with Gen 3 Hemi
 

Andrew,

Is there a Mopar ECU/TCU solution for this trans with Gen 3 Hemi? Or is it the same situation as with the non-Mopar engines ...

I have no idea. I don't work with OEM ECUs. I only work with Holley EFI and you can use Holley EFI on Gen 3 Hemis.

Andrew

That's moving damn quick.

Little action from last Thursday.



We were making consistent 10.9x passes at 124.x MPH. Sixty foot times were in the 1.5x range. This was done with over 100 pounds of subwoofers and a spare tire in the trunk.

Andrew

Here is a cool product that you guys might be interested in:

https://www.crossmembers.com/product...n-gf-mut-8hp70

I will be using it to mock up the 8HP70 in my Cougar, along with their Godzilla mock-up block.

​​​​​​​Andrew

Those things are great for easier swap prep + validations.

This is one of my customers cars:

https://youtube.com/shorts/vUFEIJCOSsY



Andrew

I have been contemplating one of these in my 72 Chevelle I have a fueltech ft 550 lite and they offer an option to tune the trans. I need to figure out a adapter plate/converter for it to mount to my Gen 1 but just started drinking that cool aid.

I don't know anything about Fueltech or their 8HP controls, but Domiworks offer a Gen 1 SBC adapter.

Andrew

I am working on my own 8HP70 swap into my 67 Cougar. I was using the 5th gen Camaro starter. Well, that starter has a unique nose on it and it does not work well with the Domiworks adapter. I recall having a similar clearance issue when I used that starter with a stock T56 bellhousing. Instead of butchering the adapter (more than I already did) I ordered this truck starter. It has a different nose, but still have the connector for the solenoid wire.

https://j.hmjimg.com/2025/06/30/1242.jpg

You can see where I have already clearanced the adapter, but had I used this starter from the beginning, that would not have been necessary.

https://j.hmjimg.com/2025/06/30/1243.jpg

The other difference with this starter is that it does not have provisions for the heat shield, like the one that is used on the 5th gen Camaro starter. I don't think this will present any issues.

https://j.hmjimg.com/2025/06/30/1244.jpg

This shows how much the bellhousing has to be notched in order to clear the nose of the starter. I could have done a slightly smaller notch, but I didn't want to keep messing with it.

https://j.hmjimg.com/2025/06/30/1245.jpg

I plan to 3D scan that area and have a small cover designed and 3D printed. The engine swap party is a little over 2 weeks away.

Andrew

The ZF8hp70 transmission fits better in my Cougar than the T56. I was able to raise the back of the engine about an extra inch, which actually improved the relative angle of the engine to the rockers.

https://j.hmjimg.com/2025/07/21/1260.jpg

This is the view on the driver's side.

https://j.hmjimg.com/2025/07/21/1261.jpg

and the view on the passenger side.

https://j.hmjimg.com/2025/07/21/1262.jpg

I used an 8HP70 mount from Holley and even recycled the transmission mount from my 89 Suburban project. I also made a new crossmember by starting with a Chris Alston Chassisworks Mustang crossmember kit. The new crossmember turned out pretty good, except when we went to install the exhaust, it hit the crossmember. :��:

https://j.hmjimg.com/2025/07/21/1263.jpg

I've had these little plastic bellhousing block off plates in my tool box for 15 years and I finally have a chance to use them. This one seals off the driver's side of the bellhousing.

https://j.hmjimg.com/2025/07/21/1264.jpg

This side loops around the started nose and seals off the passenger side opening.

https://j.hmjimg.com/2025/07/21/1265.jpg

I ordered a small Earl's cooler to use for the transmission and we found a good place for it on the side of the hood latch support.

https://j.hmjimg.com/2025/07/21/1266.jpg

My buddy Brian took this shot after we got the hood back on it.

https://j.hmjimg.com/2025/07/21/1267.jpg


Saturday afternoon FedEx delivered the blower belt and a few minutes later....



Tom handled the transmission fluid fill procedure while Brian shifted through the gears, which is required to fully fill these transmissions.

Yesterday I ordered a dual CV driveshaft from The Driveshaft Shop. In the meantime I need to permanently wire the TurboLamik and figure out a way to mount the BMW shifter. Ideally I would make a console, but there isn't time to do that before LS Fest.

Andrew

Following along on this... I think I'm going to swap the TR6060 in my Mustang for an 8HP70 this winter. Not shocking to find you're way ahead of me on your builds.

I wish they made one of these I could fit in a Corvette transaxle. :D

I'll just leave this here:





Andrew

Stock 8hp70, stock converter, 10.2

That's rad.

Very impressive! That’s a great ET for a street car. Well done!

Last week I took a spare 9" carrier, that I have been dragging around for about 8 years, to a recommended shop to swap out the ring and pinion. This was a Currie nodular 9" carrier that came with a 31 spline True Track diff, but had a useless 4.57 ring and pinion gear.

A while back I purchased a used OEM 2.75 ring and pinion and also a REM polished 2.75 ring and pinion from Quick Performance. I told the guy to use whichever gear set he felt would be the quietest. HE ended up setting up the used OEF Ford gear. I started the carrier swap yesterday and finished it up this afternoon.

I took my first drive and I have to say, that in my opinion, this is the optimal rear axle ratio when using the 8HP70 transmission. The gears are very quiet and I am pretty pleased.

For anyone contemplating the 8HP transmission swap, I would use either a 2.75 or at most a 3.00 gear set, assuming the typical 25.5 to 27 inch tall tires that we all use. With a taller tire, a 3.25 gear would work as well.

Andrew

I wondered about this. Once the ability/possibilities to swap these transmissions started growing, I did rpm calcs to figure out what gearing options might be most beneficial. I was curious on the numbers....