Very much still in progress, haha. I took essentially a two week break before I dive into floor rebuild and clutch modification. The only things I've done recently are design, install the P/S high-pressure line adapter and a new return line. Old one was dry-rotted out.

The CAD program is called Onshape. It's online and free, if you're interested in trying it. If you do, I can share all the TDPs I've created. I'll update the tunnel design for a 4L80 version, and tweak it for improved/ease of fabrication, send you the blueprints this weekend.

This clutch system is what I've come up with:
Light Blue- Firewall representation
Light Gray- clutch master cylinder/ piston rod extension
Black- GTO clutch pedal Red- modification to clutch pedal
Gray- "Rail"
Dark Gray -"Carrier"
Green- GTO mounting bracket, modified
Red- Clutch arm modification with pin
Cyan- 3D printed column mounting bracket (still in progress)

The original GTO clutch master cylinder mounting won't fit immediately where it would theoretically be mounted on the firewall. The Catalina's fuse block, wiper motor, and brake booster prevent it. It can't go below those because the lever- advantage needs to be around 10:1, and the highest location on the firewall below the brake booster only gave a 4:1 lever advantage (and of course I only figured it out after I had dremeled holes in the firewall). I can't put it inside the cabin due to space restrictions, or below the floorboard due to mechanical design restrictions. So if you can't put it high or low, can't put it right or left, can't put it more forward or further back, where the hell does it go? That's right, it goes on the fender with a ridiculously complicated system of sliders, pins, and slots to transfer the arc motion into linear motion! And I get to use the two square inches of firewall real estate between the booster, wiper motor, and fuse block for the clutch piston rod extension.

I'm gonna be spending a lot of hours on the Bridgeport. Anyone else think I should TiN coat them after heat treating? Obviously just being 4140 chromoly is not enough overengineering.

 

Maybe no help but on my 68 C10 I used a 2004 C5 brake booster. Dual diaphram. Much smaller than the stock booster diameter wise. Stock clutch pedal. Wilwood clutch master. Hard line to a bracket under the booster. Flex line to the slave. I also moved the fuse block to clean up the wiring. Pic.

 

Damn, that's a clean engine bay!

 

Thanks for the kind words.
I do try to hide all the wires as much as possible.
Current project is a 80 Camaro with a LS3/4l60E swap.
Again most wires hidden.

 

Not sure what your brakes are, but a C5 master booster may not move enough fluid.

This is an idea that may work to use the 4:1 lever you need but still drop it enough to clear the master/booster. The arm can be laser cut steel welded to a 5/16-24 coupler nut (whatever your clutch master uses). It would pivot less than the pedal swing.

 

C5 13" on the front and 2002 Camaro 12" rear discs. Wilwood prop valve to tune in the rear discs.
Zero issues braking.
I run small cams so I have plenty of vacuum for the booster.
I've used the same combo on both the 73 and 79 Camaro. The above 68 C10, 80 Camaro and a 67 Nova with non-power brakes. The 67 I used a Wilwood master specced out by Tobin@kore3.com. The 67 worked well you just had to push a bit harder but zero issues stopping.
I like using the C5/Camaro stuff because you can get replacement parts at most part stores.

 

Just one more thought.
Have you considered a hydro boost power brake system. They are pretty compact.
I used one a number of years ago on a 66 Mustang project. Again C5 front and 2002 Camaro rear brakes.
The 306 small block had a pretty good sized cam so no vacuum for power brakes.
I bought the hydro boost system from Paul at Hydratech. They would put your nose up against the windshield.
Your car is pretty heavy weight wise. Might be a good fit.

 

I second the hydroboost. One of my first hydoboost swaps was from Hydratech. I have done 7 or 8 hydroboost setups for me and more for others. Never disapoint.

 

What about a remote booster? Anyone ever worked with one of those? My dad gave me one he had leftover from one of his older projects. Not saying I'm married to the idea, just that it's already paid for and in my hands.

 

Watching this thread closely, '66 Catalina in the barn & an 07 Yukon donor just "appeared".

Excellent work/info thus far...

 

Been a hot second again. Gotta stop that from happening. Long story short, I got the floor installed and repaired. I fabricated seat's rear mounts. Took me two days to figure out the angles with blocks of wood and repeated sitting tests. I measured, located, and welded said mounts in place, re-using one of the original captured nuts as the outer front locating holes. I also added two new frontal mounting points towards the tunnel in the form of weld nuts. I didn't make a layout design for this one, just kinda eyeballed it. It turned out decent, but I was sloppy on the punching and folding of the mounts' sheet steel. This week I want to grind/seal/paint, make it presentable and ready for... Whatever's next. Maybe soundproofing? No, probably need to rebuild the front clip so it can actually hold a battery.


Why it looks almost passable as decent work! It's not, but it looks that way!

 

Welp, looks like I made an error- bought an EFI- ready Impala tank from TanksInc but misread the dimensions- it's the opposite direction of what I expected, wider than long rather than longer than it is wide. Oh well. My username is accurate, once again. This time I will pay for it in sweat and blood as I modify the straps to hang it. The exhaust had to be taken down anyways so I will re-route it around the wider tank. Beware, ye who read this thread for their own Pontiac!