Is it safe to replace 1 shock on a high mileage car?

[911monty]

Gotta say that I can clearly see why they only want to change one strut now! The potential suspension geometry handling issues from a bent frame would be masked by the belief the poor handling was being caused by the mismatched struts! If the chassis is bent the mismatched suspension geometry will make the car handle more like a 70's Vette. You are there but if the shop hedges on "if we can't align then we'll check the chassis!" then THStone is correct, Get a new shop!