Proflow's single-plane Max Jnr Intake manifolds are very versatile and can be used for drag racing and Oval Track competition, as well as for street applications. Power bands range from 3,500 to 7,000 rpm, on up to 4,500 to 8,000 rpm. There are applications for small block and big block engines, as well as for 2-barrel and 4-barrel carburetors.