There were quite a few different steering boxes offered for the Corvair. Internally they are pretty much the same, but there are some differences.
60-63 CARS - these are easy to identify because they use an all-aluminum box and have a very short worm shaft (about 1" out of the box). This box is also the preferred choice of street rod and dunebuggy users.
64 CARS - the first year to use the cast iron box, these also were the first to use the totally unbelievable full length worm shaft - the shaft runs all the way up to the steering wheel! This box is easy to confuse with the almost identical early 65 car box so measure carefully! The diameter of the worm shaft is .625 (5/8ths inch) and the overall exposed length of the worm shaft is 49 inches.
65 CARS - non-telescopic - now it begins to get more complicated! All cars from 65-69 have cast iron boxes. MOST 65 car boxes are of this type - shaft diameter of .625" and an overall exposed length of 47 1/2 inches. However, sometime late in the production year the shaft was shortened to the intermediate length used on the 66-67 boxes (listed next). IN ADDITION if two different 65 boxes aren't enough there are two more! Telescopic and quick steering!
65 CARS - telescopic - in 1965 Corvairs were first offered with an optional telescopic (adjustable) steering column. Naturally the box is different too! The worm shaft length is approx 14 1/2", and uses the earlier style two-bolt simple coupling. Or at least that is how the early 65 telescopic boxes are! Later in 1965 both the telescopic and non-telescopic boxes are the same with a worm shaft length of 15 1/2". 66 CARS (also late 65) - the worm shaft length of these is approx 15 1/2 " and use the double nut coupling with the large bell-type shield. Note that telescopic and regular boxes are the same for these years.
67-69 CARS - these boxes would look almost like the 60-63 type except that the housing is cast iron (like all 64-69). The worm shaft only sticks out about an inch or so. Again, as with the 66 boxes, telescopic and non-telescopic are the same.
QUICK STEERING BOXES - this option was first available in 1965 and are fairly rare. The box will appear to be the same as a regular or telescopic box BUT with the box removed from the car check the turns lock to lock. A standard box will turn approx 5 1/4 turns, while the quick steering box will take about 4 turns. Installed in the car lock to lock turns for quick steering will be about 3 1/2 turns because the option also included special quick steering arms to shorten the turns even less.
61-65 FC (Vans, Pickups) - these are not to be confused with any of the car boxes! The box is
very heavy cast iron with a full length shaft and shield.
Our thanks to Professor Larry Claypool of the Vair Shop, for his assistance in compiling this information!