can you use an HL-365b? Its the gas version tilly used on the Tecumseh Motorsports H50 (5hp) engines. I have a used one I will sell for about around half price of what they list for as I am float carbing a Motorsports engine that I am building.
PM me if you can use it, I cant help with what people used on the briggs etc, as I really dont pay attention to that stuff.