Galbreath Glow heads
I use the Galbreath Heads & am very satisfied. The compression ratio is better than the original Cox head. The Nelson plug replacement is only $3.00 compaired to the $10.00 to replace the Cox head. The Nelson plugs are designed to accept a lot of nitro without failure. I run 65% nitro in my Cox engines, & they really turn on with the rpm.
Gene Wicks