HotWheelsBurban
Full Access Member
- Joined
- Mar 31, 2023
- Posts
- 2,736
- Reaction score
- 6,711
- Location
- Houston, Texas
- First Name
- Carol
- Truck Year
- 1990
- Truck Model
- R2500 Suburban
- Engine Size
- 350
Should be a 14mm; I would think there is a special made tap/thread chaser for that. Do you have a well stocked parts store near you?Anyone know what size tap a spark plug hole would take on a small block?