Technical trans tunnel offset?

Building my 1932 Ford roadster's trans tunnel today. I'm 6'6", so leg room is important.
How much should I offest the trans tunnel from the trans? How much air gap between tunnel and transmission?

Thanks,
Scott

 

A paint stick thickness will be fine.
Keep in consideration should you need to remove the trans how you can do it.
make sure driveline angles are set then build whatever shape you need to cover it.

 

What type of transmission?

 

I'm going thru a trans removal right now in my '46 pickup. The tailshaft broke. The trans needs to slide backwards to get removed. Otherwise I will have to pull the engine and trans out from the front as a unit and that is lots of work I'd rather not do, removing the front clip, etc.
I suggest leaving enough space to be able to slide the trans rearward to disengage the torque converter (or manual input shaft) from the rear of the crankshaft. Tilting the engine down rearward may also be helpful. Mine is going to be tiiiight.
Also, I made a pair of these pyramid step blocks to help me determine tunnel height and conical taper.
pictures to follow

 

This tunnel was built tight but with enough room to slide the trans back if necessary for removal


my current beater has a bolt in trans cover. Makes adjustments and other issues easy to deal with.

 

My trans cover is removable for serviceability

 

TH350, 327 Chev

 

I'm most likely going to make it removable!

 

First thing is you need to put whatever seat(s) you plan to use in the car and see what you would like to have vs what you must have for leg/foot room .........
Then see what your transmission will allow.
If everything isn't sufficient, see if its possible to lower your engine mounts and trans mount an inch or two. Don't know if thats possible because I don't know how far along your build is. Since most auto trans are round on the top, slight lowering can increase space quite a bit.

While having it removable is nice, it would require pulling all your carpet to access it and doesn't give more leg room. You just need to insure that the extreme forward portion of the tunnel is high enough to get a socket between the tunnel and the trans. That area doesn't affect foot room.

 

Thanks...
This is a ch***is from a car I built 20 years ago (had a fibergl*** duece customs 3 window body on it). In that car, the setup was great.
I bought the rolling ch***is back from the guy I sold it to 20 years ago...it was originally set up as a small block Chevy with a TH350, so I'm doing the same thing this time.
That deuce customs three window body had a one inch square tube frame underneath the floor that supported the steel floor, so this Brookville body will actually give me an inch more leg room downward.
If I remember correctly with the original coupe build, the transmission tunnel was very minimum. I just made a cardboard template for the cutout and I think I'm going to weld the tunnel in.

 

I've obviously got to make room for the transmission dipstick so I think I may offset the tunnel a little bit on the p***enger side to accommodate.

 

Mine is an integral part of the floor. After making the cut for the 350 trans there wasn’t much floor left. In the interest of making it ridged, the floor and tunnel are 10ga. As is the fire wall.

 

An automatic trans needs a larger removable cover than a stick if you want to get to the bellhousing bolts. So consider that if you build a removable cover. I have extremely tight clearances in my tiny Austin g***er, as the interior is only 42" wide and two bucket seats nearly touch each other inside! So I built my trans tunnel tight. Too tight, as I had to replace the flexplate, and after dropping the crossmember I still couldn't get to the upper bellhousing bolts!
I ended up carefully measuring out the bolt pattern on the bellhousing, and then drilled small 1/8" locating holes to see how close I was. Then adjusting slightly and drilling 1.125" holes with a holesaw over each bolt head. Then I was able to remove the upper bolts, and lower the engine/trans enough to slide it back and replace my flexplate.
Afterwards I installed 3/4" pipe knockout seals in each hole, which are actually for 1.125" holes. Now if I ever need to pull the close fitting trans I can remove the seals and easily take the bolts out. If I did it again I'd make a crescent shaped access cover to get to all the bolts I can't get to from below.

 

That's along the lines of what I was thinking, nice!

 

The edges get painted black to match the floor. 32 Ford roadster with a 2004-R

 

Good idea. I'm going to use your idea.