For those who have made they're own steering columns i have a question, is there a limit to how much shaft that can extend from the firewall ? Can I use one piece of shaft from the steering wheel to a u-joint and then connect the u-joint to the steering box and if I do, do I need to support the shaft in between the firewall and the steering box ? Mine will extend about 18" - 22" beyond the firewall
With only one U joint, it should be ok. The problem is when you have more than one U joint, you need to make sure there's a support near each joint
It probably depends on the particular situation. If there are two U joints, which is how it normally works out, then you would only want to extend the shaft about three inches, to provide support for the upper U joint. You do need to be careful with alignment, so there is no binding, if you only have one U joint, It might be better to use two for that reason.