Demon Carb

The road Demons are not the same. They have that tube that connects both fuel bowls.

The speed, mighty and race Demons are based on Holleys 4150's. The road Demons might be based on those other Holleys that use a tube to feed the fuel bowls.

As for just taping the next size up, you can. Use a 1/4 tap, no need for a coil or insert but the fuel bowls holes and metering bolck need to be opened up a bit.

PS never got to try my new carb yet, First the streets were all wet, then the snow came, now its zero degress outside.