- Joined
- Jul 12, 2010
- Messages
- 5,427
- Reaction score
- 3,693
- Location
- Killingworth, CT
- My Car
- 71 Mach 1
71 XR-7 hardtop
71 Country Squire
65 hardtop
Water pump hub is threaded for 5/16-24 fine thread. You can use regular hex bolts if you prefer. The factory 5-blade flex fan was 18 1/2", so the 18" would be best.