1970 GTO V3

[andrewb70]

I think most of you know me, or at least know of me. My name is Andrew Borodin and I have been a part of the pro-touring community for a very long time. I have a 1970 GTO that I first built about 20 years ago and was on the cover of Popular Hotrodding in 2003. I was also the winner of the 2003 Car Craft real Street Eliminator competition in the summer of 2003 and was featured in Car Craft magazine.

The car was originally built with a 502 big block with Holley EFI and a Richmond 6 speed. In 2008 I did a LS swap with basically a LS3, LS7 cam, and kept the Richmond 6 speed. That build can be seen here:

https://www.pro-touring.com/threads/...TO-Version-2-0

In 2014-2015 I also built a LS swapped 67 Mercury Cougar and that build can be seen here:

https://www.pro-touring.com/threads/...res-and-videos)

In those years I have also moved a few times, earned a Ph.D. in marketing, and now run a full-time Holley EFI tuning business, aka Dr. EFI.

That about brings us to the latest version of the GTO. This project actually started a little over 2 years ago. The original plan was pretty straightforward. I wanted to do some simple upgrades and drive the car.

As we all know, things change, and I decided that I wanted more power. I also wanted to experience a turbo LS with an automatic transmission.

The whole journey can be seen here:

https://www.pro-touring.com/threads/...TO-Version-3-0

For the purposes of posting here, I think I will start with the day that the car went to my friend Vic's house. I met Vic about 2 years ago when he contacted me about doing some tuning on his beautiful 57 Nomad. Since then we have become pretty good friends and he was gracious enough to help with this project.

I can't thank him enough because he has skills and equipment that I don't and without him, this project would not be where it is today...

This will be a bit of a copy and paste dump, so please bear with me. I will tag each post with dates for context and bring y'all up to where we are today.

Stay tuned...

Andrew

[andrewb70]

Date: 10-27-22

Yesterday was a beautiful fall day and it gave me the opportunity to get the GTO to Vic's house.



After I get back from SEMA, the plan is to start cranking on it and get the engine and transmission installed and start on the turbo fab work.

Andrew

[andrewb70]

Date: 11-20-22

Today was a big day. I went over to Vic's house with the goal of mocking up the engine in the engine bay. I had confidence that the Holley swap components would not be an issues, but the big area of concern was the oil drain back fitting for the turbo on the side of the Holley 302-3 pan. Holley designed those drain backs in a Fox body Mustang, and when used with a GM A-body there was some concern that the fitting would hit the front crossmember.

These are the Holley clamshells with the poly inserts. They are dimensionally identical to 4th gen Camaro engine mounts, except with a bolt together design and poly inserts.



I am not sure why Holley includes such long bolts, but I decided to keep them and the included lock nuts. They will not be visible at all once everything is bolted to the engine.



After mocking up the engine the first time, it was clear that the oil drain fitting that I got was not going to work. At least not without some modifications.



I can't believe I have gone this long without having a lathe and a mill. Both were used to modify the Earl's fitting in order to make it fit.



The lathe was used to back-cut the area between the end of the threads and the hex area. This was done so that the fitting can be installed deeper into the boss on the side of the pan. The mill was used to trim the end of the threads, because with the fitting screwed in deeper, it would hit the oil pick-up tube.



The outside of the fitting was also smoothed and contoured on the belt sander. It is a rather bulky fitting and there was plenty of material to remove in order for the fitting to match the contour of the front cross member. The pan was also removed in order to tap the 1/2" NPT threads a little deeper.



It took a total of six rounds to get it to the point where the engine mounts dropped into the frame stands and the mounting bolts to slide in.



The fitting has about 1/8" clearance against the crossmember, and it is able to pivot freely.

With some luck, the transmission and the converter will go in on Wednesday and then Vic can start the fabrication for the turbo hotside.

Andrew

[andrewb70]

Date: 11-23-22

Today was another big day. I hauled all of the parts that were needed to install the transmission to Vic's house. We started around 10am and made excellent progress.

This is a billet steel SFI approved flex plate from Circle D. It looks amazing and has 6 converter bolts to match the Circle D billet triple disk converter.



It is nice working with a clean block and a new crank. Just to make sure everything was good, I hand threaded the ARP flex plate bolts into the crank before doing anything else.



The flex plate went on without any drama and was torqued to 75lb/ft using blue Loctite. The flex plate locking tool came in handy for this task to keep the crank from rotating.



After installing the converter into the transmission (not sure why I didn't get a picture), it was time to wrestle this beast of a transmission under the car. We had some jack stands under the rear axle and jack stands under the front frame horns to get the car high enough.

It was easy enough to get a jack under the tailshaft housing, but getting the front of the transmission up was the big challenge. I suggested using the engine hoist and attaching a strap to two bolts in the transmission case. This worked great! We got the transmission high enough to slip a transmission jack under the pan for extra safety, then slowly working it up until the transmission slipped on to the dowel pins.



There was about a .130" gap between the converter and the flex plate, which is perfect. You can see that the pan is basically level with the frame.



We followed the instructions that came with the Holley transmission crossmember, but had a little trouble with the transmission mount that I got. I got an Energy Suspension poly mount, which is not what is specified in the instructions (should have read them before buying it). After a little searching around on Rockauto, we got a part number for a 70 GTO TH400 mount, Anchor PN 2378. The local parts store had one in stock and it ended up being about 1/2" shorter than the Energy Suspension mount. This allowed the crossmember to slip under the transmission easily, with about 3/8" of clearance.



The left side of the crossmember slips over the frame rail, while the right side (shown here) has a separate pad that slips over the frame rail and the crossmember sits on top. This makes for a really solid installation.



Part of the reason I ever started this project was to redo the engine and transmission mounts and use a better fitting oil pan. I can't say enough about how well the Holley swap components are engineered to work together and how well everything fit together. In this day and age, it is hard to find parts that don't need some sort of modification to work as intended. We didn't have to modify anything!

Now that the engine and transmission are in their place, the fun stuff can start...

Andrew

[andrewb70]

Date: 11-25-22

Today started out well. The driver's side manifold installed with zero issues and fits perfectly.







The same could not be said for the passenger side. I can't believe that I never mocked up that side with the engine mounts when the engine was on the stand...

When I went to install it on the engine, it was obvious that that manifold was hitting something and it was not sitting flush with the head. We used some clay on the manifold and here you can see where it was making contact with the engine mount.



We were pretty confident that the engine mount clam shells were assembled correctly and the poly inserts were oriented properly. Otherwise the engine wouldn't have fit into the frame stands as well as it did.

Here you can see the contact spot on the manifold.



We jacked up the front right corner of the engine and removed the engine mount.



I really didn't care why it was happening, we had to fix it and keep moving forward. Vic chucked up the engine mount in the mill and we took off about .080". The material is pretty thick, so we felt confident that the integrity of the mount was not compromised. Besides, the upper clam shell is really not stressed when it is installed on the passenger side.



Here is the final version of the passenger side mount after a quick coat of paint. Onward!



We used Mahle MLS exhaust manifold gaskets. These should seal really well and hold up to the heat.



We then installed the radiator and fans to see what kind of room we had to work with.



Here is the 135 degree elbow that I got from Stainless Bros as the starting point for the turbine up-pipe.



We're thinking the turbo is going to end up next to the AC compressor, oriented parallel to the engine.






Sunday we are going to do some more mocking up and maybe make a temporary mount for the turbo so that the pipes can be figured out.

Andrew

[andrewb70]

Date: around 12-2-22

Today we attempted to mock up an approximate location for the turbo. We hung it on an engine hoist and moved it around. The following pictures show various options.


















The challenge is to find a location that clears the following:

Heater hoses
AC lines
Lower radiator hose
Air filter

Bottom line, I don't think any position will work. This thing is just too big...

Andrew

[andrewb70]

Date: around 12-4-22

After taking a break and stepping away from it, we came up with this placement. The wood is there to simulate worst case scenario hood clearance.


















The center of the turbo is even with the Maven turbo mount. This will allow us to make a simple bracket from the head to help support the turbo.



This turbo placement allows for plenty of room for all the necessary bits to clear and also gives a clear path for the turbo drain.

The inner fender will have to be modified, but that is a problem for future me...

Andrew

[camcojb]

Thanks for posting up Andrew. Great car with a lot of history.

[andrewb70]

Sure thing. I'll post more later today.

Andrew

[andrewb70]

Date:around 12-6-22

While waiting for a few small parts to arrive we decided to mock up a few intake arrangement options. My original idea was to have a side entry lid facing the passenger side. This arrangement will make it a challenge to snake the charge pipe from the compressor outlet to the throttle body, but I think it can be done.



This is an alternative side entry. Obviously the charge pipe will be longer, but the path should be easier to lay out.



This is the front entry options. Again snaking the charge pipe will be a challenge, plus, I am pretty sure the peak of the lid will hit the hood.



Front view of the front entry option.



You'll have to use your imagination and add another 3" to the front of the intakes for the throttle body.

Andrew