Hey, OE Parts Headquarters here. We have water pumps in stock from ACDelco that fit F series trucks from 1987-1996 with 5.0L and 5.8L V8 gas engines. The link below should take you to our site and display the part.
The water pump is a 252-673 and sells for $41.73 each.
This is a genuine ACDelco part and comes with a one year manufactures warranty. UPS ground shipping would be $6.99 but there is no sales tax. If you have any questions or concerns please feel free to send us a PM or email us at firstname.lastname@example.org