Enderle K-style Barrel valve refurb kit
The best kit out there for freshening up your barrel valve.
This kit not only provides all the correctly sized methanol/nitro safe o-rings and metering piston clips, but also new stainless AN washers and nylock nuts for reinstallation on your hat. O-rings are included to refurb the -6 check valves (2 ea.) as well.
If your application requires gasoline compatible o-rings, please specify in the comments section of your order.