There is a difference, I've got it in a handy Volvo book around here, there's something like 18" difference, the 1.4 has the best, then the 1.7 and 2.0 manual racks, then the pas. I'll try and dig it out.

I'd love to see the spec for PAS and non-PAS difference. There is supposed to be a difference between 1.4 and 1.7/2.0 but the steering rack part numbers are the same for 1.4 and 1.7. I couldn't find any difference in spec between PAS and non-PAS, apart from number of turns lock to lock then again, I didn't find any decent specs on PAS turning circle