Looking for 17" diameter 7 blade mechanical cooling fan...non clutch

I need you to measure exact point tip to across point tip....go across the center hole to make sure you are at the widest point.........They both look like 18 inches at the widest possible point across.....I already have a 7 blade 18 inch diameter and the widest I can get my shroud on the radiator is 18-3/4 which is too close for comfort for me...It only gives me about 3/8 buffer on each side.......So I was wondering if they made a true 17" fan at the widest point.....Which would give me 7/8 buffer on each side.....I would feel much morte comfortable......