I'm putting a 5-speed trans into my 67 Barracuda. I had to open up the tunnel and I'm now rebuilding it. How much clearance between the trans and the tunnel do I need? I was thinking a minimum of 1/2", but I'm not sure how much the transmission will be moving around. Rubber mounts all around if it matters.

Thanks for any help you can provide.

What I'd do is measure how much clearance is there on one of my other Mopars than duplicate that amount

Just a bit of advice...I would check your front universal joint angle so that you will be able to move the tranny tailshaft up if you need to before you finalize your tunnel. I installed a 5 speed in my 68 b-body and checked my front operating angle and it is slightly pointing down instead of upward. I can't raise it up anymore in the rear because of the tunnel.

Your should strive to have equal and opposite angles from the rear end /driveshaft angle to cancel out any viabrations. The rear usually points down about 3-7 degrees, so the tranny should be pointing up about the same.

tunnel top

tunnel bottom

top finished, hope this helps

Thanks for the pictures. How much clearance did you end up having around your transmission?

Driveline angles were already checked and are okay.

Most of the stock Mopar V8 cars I've checked, A,B and E bodies, had the pinion gear pointed up towards the tranny, not level or down BTW, there are probally 10,000 different ideas and theorys on this site about the "proper pinion angle and the pinion angles relation to the tranny output sgaft angle" The most important thing to make sure of is that the driveshaft is not perfectly aligned with the tranny output shaft and pinion shaft All automotive U joints need a small amount of difference in angle, up or down , left or right, to make the needle bearings rotate inside of them to prevent binnelling, galling(SP?)I would want enough room for air to circulate around the tranny to help keep it cool

Most spots are well over 1". It does have an area at the left rear corner of the shield ( next to the bend in the shield) that is about 1/2". It's strictly a drag car so I wasn't worried about rattles, just ease of service. As far as drive line angle it's very simple. The trans output shaft an the pinion should be parrallel. If the car will be drag raced the pinion should then be nose down an additional 1 1/2* to 7* depending on rear suspension type. I found 5* down with stock leaf springs works well and doesn't vibrate on my street car
Doug