carb adapter 2bbl to 4bbl Fits any 4-bolt, 4bbl to any small 4-bolt,2bbl manifold and/ or 4-bolt,2bbl to any 4-bolt,4bbl manifold (except spread- bore applications).Measures 1" nominal height of adapter only without gasket. These carburetor adapter kits install quickly and easily. Gaskets, studs,nuts and washers are included. Adapters are made of diecast aluminum.