Follow-up on my previous post and Paul R's comments.
I spoke with Gil Evans, my contact at Borgeson. The cost of a flanged, collapsible column, that attaches to the existing "rag joint" is in the $190-$200 range, for the complete replacement part. It is not being produced for the B-body at present, since there has not been sufficient demand.
The unit I have is plain steel, and has 2 universal joints, the lower one replacing the "rag" joint with an isolator/U-joint combination that attaches directly to the steering gear spline shaft. According to Gil, this unit will cost about $250. While this may seem "alot", the part is generally superior to stock, gets rid of the rag joint, and has a 2-year/30,000 mile warranty (no I don't know how they enforce the mileage part of this). The reason Borgeson is using the isolator/U-joint design for now, which is why it costs more, is thaat the shaft can be cut to length, where the rag-joint type is a fixed length. You can use stainless steel U-joints, but the collapsible shaft is only available in regular steel.
As far as Paul's comments about poor fit at the steering column, Gil understands what he is referring to, and it may be a matter of whether the bolt or pin that secures the double-D joint goes through one or both flats of the D-section of the joint. I'll get a further clarification on this, but I don't think there is a problem here--I'll take the information and put it out here, but I do expect I'll find that I like the Borgeson shaft better than the stock unit.
Borgeson does acknowledge that heat is still the enemy, and it would not hurt to protect the upper U-joint from an exhaust that is closer than 2 inches to the joint.