RE: Best Firewall Sealer
No need to seal it with anything the JB Weld will do the job. With sealing it you run the risk of weighting it down which could cause the carb to flood. It should be real easy to find the pin hole or leak. Most brass floats when they leak it will be along a soldered seam. JB Weld is perfect for this and is impervious to gasoline.
Vince