[6567GTO]

I recently installed a TKO600 overdrive trans in my 520 hp 65 GTO hardtop coupe that I bought from Classic Chevy 5 Speed in CA and thought I'd share the experience with you all.
In total I'd say the job took a couple days to do by myself. If you have a reasonable amount of skill working on cars you should be able to do the same thing in your Pontiac without too much trouble.
I chose to go with a .64 5th gear ratio. They also offer a .82 road race ratio.


The Installation:
First I removed the front half of the interior including the seats, sill plates, kick panels and carpet. I then jacked the car up as high as possible to allow for ample room when removing the old trans and for installing the new. I placed the jack stands under the rear axles and under the front spring lower A trays. Next I disconnected the exhaust which is an aftermarket system. Then I removed the driveshaft followed by the shifter and then the Supercase Muncie. I decided to leave the clutch assembly alone at this point because it was working just fine and therefore left the scattershield in place as well.
I then climbed back into the car and traced out the area which I'd need to cut on the tunneling to clear the new Tremec. Tremecs are a little larger and boxier then Muncies so this part is necessary in order for it to fit. Once traced I proceeded to use a 4" hand grinder fitted with a cut-off wheel in cutting the tunneling.

[6567GTO]

more pics:
The Template

[6567GTO]

After the cutting:

[6567GTO]

Here are some picture s of the trans and the offset shifter I bought. I bought the offset shifter and am glad I did because it brought the shifter to the proper location for me to shift and if I ever decide to reinstall my console it would be needed to fit the shifter hole.

[6567GTO]

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[6567GTO]

After cutting the floor it was time to install the TKO. I used a floor jack and a lot of muscle to get it in. They're a heavy trans and I wish I had someone there to help me at this point but I managed.

[cwolf]

Good luck with your project.I'd like to hear how it drives when you're done.

[6567GTO]

..

[6567GTO]

another shot:

[6567GTO]

With the trans in place I started to install the Indian Adventures driveshaft safety loop and transmission mount but realised that the boss under the tail section of the trans had to be removed. Out came my sawzall!

[6567GTO]

,

[6567GTO]

another angle
Not pretty but it worked!

[6567GTO]

The location of the trans mount is just under 2" further rearward so another set of holes had to be drilled in the frame for the crossmember mounts. And because I have headers and cutouts I had to notch my crossmember in one spot to clear the exhaust.

[6567GTO]

After the crossmember and trans mount was bolted and tight I took measurements for my new driveshaft. All this is clearly explained by the guys at Classic Chevy 5 Speed in the paperwork supplied with the trans. At this point I stopped and had to wait for the driveshaft to be made. Jeff Mortenson at CC5Speed promised a quick turnaround and he delivered as promised. I had a new driveshaft in my hands in roughly 5 business days after sending them the info! Remember, he's in Cal and I'm in CT! Talk about fast service.

With the driveshaft in place I pumped in 3 quarts of GM Synchromesh. $10.20 a qt!

[6567GTO]

Next I made a template out of cardboard in order to help in making a sheetmetal replacement floor tunnel piece.

[6567GTO]

and the sheet metal piece...

[6567GTO]

I then pop riveted the new metal in place and spot welded the entire edge about every inch or less. A friend of mine lent me his mig welder for this. After the welding was done I ground down any bad welds and sealed it with body seam sealer.

[6567GTO]

I then painted the new sheetmetal with some POR-15

[6567GTO]

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[6567GTO]

Once it was dry I reinstalled the carpeting followed by the sill plates, kick panels and finally the seats. The last thing to install was a new shifter boot.