1970 GTO Version 3.0

[andrewb70]

I am making slow progress. In the last installment I posted the bracket that will hold the Holley Dominator ECU and the Hardwire PDM. Today I got a care package from McMaster Carr with some hardware.

The Dominator case is not supposed to be grounded to the car chassis. It actually has plastic and rubber mounts that are already inserted into the case. However, to isolate it more, I used rubber nut threaded inserts. To fasten the auxiliary bracket to the main bracket I used U-nuts.



Here you can see how it all fits together.



Unfortunately, the holes in the PDM are too small for #10 screws, so I have to #8 screws and corresponding U-nuts. I used a temporary support for picture purposes. LOL



Andrew

[andrewb70]

Andrew

[FLYNAVY53]

Looking forward to seeing the progress on getting the Hardwire PDM up and running....planning on using one in both the Corvette and Suburban eventually

[andrewb70]

Looking forward to seeing the progress on getting the Hardwire PDM up and running....planning on using one in both the Corvette and Suburban eventually

Awesome! I have already done some bench testing and everything seems to work as advertised.

Andrew

[David Sloan]

Sweet
That looks so good!

[slazisme]

Andrew, thanks for sharing some of the links of the companies that you have used, I've added them to my car folder of info.
I never knew about the transmission swap info that you posted, nice! In for more updates along the way.

[andrewb70]

Sweet
That looks so good!

Thank you!

Andrew, thanks for sharing some of the links of the companies that you have used, I've added them to my car folder of info.
I never knew about the transmission swap info that you posted, nice! In for more updates along the way.

The 8HP transmission swap is amazing. I am really excited about that.

Andrew

[andrewb70]

Life, work, and other projects have taken priority, but I am getting everything together to do the 8HP90 swap in the GTO after LS Fest.

Instead of doing the typical adapter plate between the engine and transmission, I chose to get one of the new bellhousing kits that is available. HPR Tuning in Norway and Domiworks in Sweden both have these available. HPR chose to offer the 8HP90 bellhousing first while Domiworks has the 8HP70 kits currently available. I am sure that at some point both companies will offer kits for both transmissions.

I also got a billet pan kit, mostly because the aluminum pan on my 90 is a little dented.









Andrew

[Just 1 More]

Those are some sexy parts

[ryeguy2006a]

Those pieces are beautiful!! Glad to see the GTO is getting some love soon.

[wfo guy]

Cool parts and good to hear from you.

[Larry Callahan]

Oh nice looking parts!

[andrewb70]

I am back to working on the GTO. Over the last couple of weeks I took the seats and the dash out, and also removed the old Vintage Air Gen2 evaporator from under the dash. In its place I have a new Vintage Air Gen 5 evaporator. I started with a universal kit because my firewall was smooth. As it turns out I still needed some parts from the 70 GTO SureFit kit and I ordered them separately.

I had some existing holes in the firewall from things that aren't there anymore, so I decided to put some bolts through the holes and make them as mounting studs.



I originally was going to use the firewall block off plate that comes with the SureFit kit, but it wasn't wide enough to span the width that I needed to use the existing studs.



So I made a new plate that spans 4 existing studs and that would serve as the mounting surface for the VA evaporator. You can see the bare steel plate behind the evaporator.

I also drilled holes in the cowl for the rear support bracket of the evaporator. Instead of using sheet metal screws, I used #10-24 rivnuts and machine screws to hold the bracket to the cowl.



There is very little room to route the hoses through the kick panel opening, but using the AeroQuip EZ-clip hose for AC and silicone heater hose should make the job easier.



Wednesday my buddy Casey is coming over and the plan is to pull the 4L80e and maybe even mock up the 8HP90 in the tunnel. We will see how the transmission fits with the stock bellhousing and the LOJ adapter plate. This will serve as a good comparison for when we modify the case with the HPR tuning bellhousing that I posted about earlier.

Andrew

[BobinFL]

Glad to see this project is back again. Always find your projects and the approach you take to be interesting.

[wfo guy]

I fully understand the "no space" comment.

[andrewb70]

Casey came over this evening and we did a thing...






More details to come...

Andrew

[ryeguy2006a]

Can't wait to see more!

[andrewb70]

Here is a big image dump. We wanted to see how the 8HP90 would fit without the bellhousing modification, using the LOJ adapter plate.

The transmission is not fully seated on the dowel pins and needs to go up about an inch, but this was as far as we wanted to push it.





























I also put the bellhousing on the block for reference.












Andrew

[Vimes]

Wow, that isn't a bad fit. It looks like a little hammer massaging on the tunnel will get it in there. How's it look in real life?

[andrewb70]

Wow, that isn't a bad fit. It looks like a little hammer massaging on the tunnel will get it in there. How's it look in real life?

It doesn't really fit without right now.

Andrew