Raising the driveshaft tunnel in my 66 Chevelle

[67-LS1]

Following my engine swap I determined that the driveshaft was WAY to close to the driveshaft tunnel. This was confirmed the first time a iAd a passenger ride in the car when the driveshaft actually rubbed the floor.
I had already enlarged the transmission tunnel to accommodate the 6 speed auto but didn’t go all the way back. I have lowering springs front and rear and dropped spindles so my car is pretty low. The tall-ish tires in the back and the 10 bolt rear end were not helping any either.
So I decided to raise the driveshaft tunnel all the way back through the back seat.
Here is a pic of where it was rubbing.

stripping out the (almost new) carpet


The tunnel being removed.

Setting the height of the new tunnel starting at the trans output yoke.

[67-LS1]

I formed some hoops from 3/16 stock to support the sheetmetal

i left floor near the original seat belt nuts.

Starting to form sheetmetal over the hoops.

I went all the way back to the front of the step up near the back seat.

[67-LS1]

Under the back seat I switched to a flat top to make it easier to modify the seat bottom frame.


Putting Dynamat down.

[67-LS1]

Now I had to modify the bottom of the rear seat frame to clear the new taller tunnel.
The forward portion had to clear the round portion of tunnel.


The rest of the frame had to clear the flat top part of the tunnel.

[67-LS1]

The taller tunnel meant the carpet no longer reached the sides of the car.

So I split the carpet in the middle and moved it out to the edges.

Then I had to reform a lot of the carpet.

I glued parts down and kept working the humps out as best I could

To hide the open center of the carpet, I added carpeted “skirts” to the side of my homemade console.

back together with approx 3” between the floor and the driveshaft.

[andrewb70]

Well done!!!

Andrew

[67-LS1]

Thanks. It was a lot of work but I don’t have to worry if any of my “plus size” friends ride in the car anymore. And I can also go to 3” dropped springs without worry. The rear is still a bit to high for me.

[De-noz]

Looks really good.
Please let me know which 6-Speed AT you use... TCI?

[andrewb70]

Thanks. It was a lot of work but I don’t have to worry if any of my “plus size” friends ride in the car anymore. And I can also go to 3” dropped springs without worry. The rear is still a bit to high for me.

The reason the rear looks high is because it looks like you have 20" wheels in the rear and 18" wheels in the front.

[67-LS1]

There actually 17’s in the front with 225/45/17 tires (25” tall) and 18’s in the back with 275/40/16 tires (26.66” tall)
So not super tall by today’s standards, I guess.
In the pic it’s sitting with 2” dropped springs in the rear and 2” dropped springs and 2” dropped spindles in the front. I have approx 4” below the front K member.
I’m thinking I could use 3” dropped springs in the rear and it would be closer to level.
Maybe I’ll add a bunch of weight to the trunk to lower it another inch at the wheel wells and see what it looks like. The rear springs are rated 124-159 lbs so I’m figuring somewhere around 300 lbs should do it.
I’ll post a before and after pic.

[67-LS1]

First picture is with 2” rear lowering springs.



The second picture is weighted to lower it 1” more at the wheel centerline.





This third picture is from the rear with it weighted down.