Can anyone out there tell me if a power steering pump for an 88 Olds Cutlass Supreme 2.8l v6 is interchangeable with a power steering pump for an 89 Olds Cutlass Supreme 2.8l v6? The pump for the 88 has a smaller pulley shaft than the one for the 89, but other than that there is no observable difference. Do both these pumps have the same pressure? Is there a reference book that tells the specs for both pumps? I emailed AC-Delco but they havent responded yet. I dont want to install the larger shafted pump if it has more pressure than the smaller shafted pump as I have already blown two rack and pinion units and just got done installing the third one. I bought a new pump yesterday,for an 89Olds, but am afraid to install it until I find out if it is interchangeable with the 88 pump. If anyone can help me with the specs for these pumps please do so. Thanks again for your time.