Hi Ed, I'm glad to assist you. Upon checking, we do not have information about the inlet and outlet diameter of this seal. Rest assured, it is guaranteed to fit the part (seal) it replaces. It is a power steering pump seal for several Chevy vehicle models. For us to check carefully and be accurate on the part you need, please provide the complete details of your vehicle (year, make, model, submodel, and engine size). We recommend you call our parts specialist for real-time, live, and immediate assistance on our toll-free number, 1-866-529-0412 (Monday through Sunday).

Hi Marx, This power steering pump is compatible with the 1990 Ford Ranger. We recommend referring to a good repair manual for step by step instructions. It may require basic automotive knowledge for proper installation and professional installation is always recommended. You can find more information here: https://www.carparts.com/blog/why-you-should-always-consult-a-repair-manual/