Collateral Damage- My 70 Chevelle site build

[waynieZ]

I like what you did, it looks factory.

[camcojb]

More progress

[Spiffav8]

Nice!! A few more small things checked off the list.

[Ricochet]

Nice progress!! I know you've been wanting to get those parts of the project done... 👍🏻

[camcojb]

Trans tunnel is pretty much done.

[syborg tt]

Looks really nice.


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[Blown353]

Make sure you have adequate driveshaft clearance to the tunnel with the driveline / u-joint angles properly set and the suspension at full bump travel. It would suck to get the car painted and start assembling and then find you have a clearance problem.

It's probably been 15 years now, but I had to slice out and raise the tunnel on my car from the firewall all the way to under the rear seat to have proper u-joint working angles and good driveshaft clearance at full bump travel, plus a bit more clearance for safety at my low ride height. I know Roadster Shop sets their frames up for low ride heights so it might be an issue on your car as well.

Didn't help I have a 4" driveshaft and was shooting for the absolute minimum working angles on both u-joints (about 0.7 degrees, just enough angle so the needles would spin to avoid flat spotting)-- that meant the transmission tailshaft had to go quite high and also had to angle the rear end "nose up" quite a bit.

Of course, with single and double CV driveshafts now being available you have a potential workaround if you need a little more driveshaft clearance and don't want to cut the entire tunnel out-- you can run increased (and mismatched!) working angles compared to standard u-joints and not have any vibration concerns.

[camcojb]

Originally Posted by Blown353

Make sure you have adequate driveshaft clearance to the tunnel with the driveline / u-joint angles properly set and the suspension at full bump travel. It would suck to get the car painted and start assembling and then find you have a clearance problem.

It's probably been 15 years now, but I had to slice out and raise the tunnel on my car from the firewall all the way to under the rear seat to have proper u-joint working angles and good driveshaft clearance at full bump travel, plus a bit more clearance for safety at my low ride height. I know Roadster Shop sets their frames up for low ride heights so it might be an issue on your car as well.

Didn't help I have a 4" driveshaft and was shooting for the absolute minimum working angles on both u-joints (about 0.7 degrees, just enough angle so the needles would spin to avoid flat spotting)-- that meant the transmission tailshaft had to go quite high and also had to angle the rear end "nose up" quite a bit.

Of course, with single and double CV driveshafts now being available you have a potential workaround if you need a little more driveshaft clearance and don't want to cut the entire tunnel out-- you can run increased (and mismatched!) working angles compared to standard u-joints and not have any vibration concerns.

I know I should do it, but was hoping I could get away without it lol. Roadster Shop does it on all their A bodies. I checked full droop and it clears but it's close. That was with stock height body mounts, RS gives you 1/2 height mounts.

I think painter Jim has a "guy" who can do this for me.

[Blown353]

If RS does the full tunnel replacement to all their builds with their frame, it’s probably needed.

Be sure to leave extra clearance to take into account for the floor flexing downwards a bit if you ever put 4 people in the car.

When I reworked my tunnel I removed the bump stops from the rear axle, pushed the axle all the way up until the axle tubes hit the frame to simulate a worst case scenario, then set 1” high spacer blocks on top of the driveshaft and set the new tunnel sheet metal on top of those spacers to make sure there would be at least 1” of clearance to the driveshaft, and then tack welded it in.

Makes for lots of driveshaft room (and the tall vertical walls of the new tunnel section actually help to stiffen the floor in bending from front to back) but it does make the carpeting job a bit more difficult as you can no longer use a standard Chevelle carpet kit. I used a standard Chevelle carpet kit for the sides but had to have a local upholstery shop do the tunnel carpet, they cut matching material and sewed welting on the ends where the tunnel portion met the floor portion.

Also had to rework the rear seat lower frame and springs in the center to accommodate the raised tunnel. It still looks stock over the tunnel, but I wouldn't want to sit there anymore... LOL

[4cefed]

You car is awesome, great work!