Bigblock intermediate shaft

The intermediate shafts are different from bigblock(bolted flange) to small block (pressed on) but does that rule apply only when power steering was ordered? Looked at a 71 all original non power steering bigblock ss car (with documentation) and it had the pressed on shaft while a buddy of mone who is restoring a documented 70 396 ss with power steering(it was a basket case) it has a pressed shaft as well-he has owned the car for a few years -but I guess it could of been changed. Both cars are Canadian built-any thoughts-thanks-keep on cruising ---Dave.