I have used 30 and 32 inch, but having said that there are variables that are unique to you, especially if you're not going to "cheat" the install with tilt. I'd suggest you use a piece of dowel(s) to insert into the universal on the steering box to simulate the steering shaft. That will do several things for you. You should do this with your engine block and exhaust manifold in place. That way you'll be able to check clearances, determine where on the floor the column should exit, or if you might need an intermediate joint to clear and still have foot room inside. Using the dowel you can then determine how far back you spot the wheel, which will be affected by how long your arms are (mine are longer than the average guy so I can get away with a shorter column as an example), what diameter wheel you use, where you locate the seat, and what driving position you favor. This will also help you determine what length of column drop to use rather than trying to adapt your comfortable position to someone elses advice. Then there are other personal preference items like how much column you want protruding through the firewall, if you need room for a clutch pedal and so on.