Eric,
Great progress.
Please post some images of the chassis where the torsion bar tube ends connects.
Strength here is critical.
On the LWB torsion bar tube, there appears to be the ‘dimples’ (green circles below) to clear the trailing arm (banana) bolts.
I don’t see any on your new tube.
These are important so you can remove the M14 bolt without first having to remove the transmission from the chassis.
While this feature was never on a SWB (I think introduced in 1971), it is very useful to not have to remove the transmission & engine to remove the trailing arm.
When you make these dimples, make sure there is clearance inside for the largest possible torsion bar.
Beginning with the ‘73RS and with all 911s from ’74, there are two reinforcements (violet illustration below) between the torsion bar tube and the rear end of the tunnel sheet metal.
This takes the load from the suspension without having the torsion bar tube trying to bend.
This also takes the torque from the bars partially away from the (side) chassis and ‘spreads the load’.
Porsche should have had these reinforcements from 1963!
Here are useful threads:
http://forums.pelicanparts.com/porsche-911-technical-forum/162568-cracked-torsion-bar-tube.html
http://forums.pelicanparts.com/porsche-911-technical-forum/181297-how-thick-torsion-bar-tube-steel.html
You should be able to find these parts cut from a ’74-> 911.
The two reinforcement ‘ears’ used to be available as a spare part.
The ’73 RS (and RSR) was more extensive with a plate extending forward through the seam and to and alongside the shift adjust opening.
Looking good!
Please keep the pictures coming.
Best,
Grady