Will these caps fit my valve stems?

These are designed for standard valve stem applications. Measure your valve stem diameter to confirm fit — most domestic and import engines use the same size, but verify before ordering if you have non-standard stems.

Do these require any prep or treatment before installing?

No prep needed. Slide them straight onto clean valve stems. If your stems have dirt or corrosion, wipe them down first so the caps seat properly.

Will the blue finish hold up to engine heat?

These are UV and heat-resistant, but direct exposure to extreme engine bay temperatures over time may fade the finish slightly. They're engineered for typical engine compartment conditions — keep them clear of direct exhaust or turbo heat sources when possible.