Be carefull how you engineer this system. A slip fit of a shaft in a tube secured by a Grade 8 bolt or roll pin through it is inviting disaster. This is not an area to take shortcuts. Use D shaped or splined shafts and U Joints secured with set screws and Thread locker. Check the websites for the major steering component vendors such as Borgleson or Sweet and follow their lead. Below you can see the lower support for the steering shaft on the footbox, it's got a caged needle bearing in it. More difficult to see is the bearing in the support that is near the rack and pinion below the lower U joint , it helps stabilize the entire shaft coupling and perhaps eliminate any potential binding. The upper part near the steering wheel has a bracket welded to a short steel tube with 2 sealed ball bearing with the shaft passing through it. The bracket is then bolted to the steel substructure that supports the windshield uprights behind the dash panel area.
Rick
