A no-nonsense, no-frills manifold for the 1-3/4" S.U. HIF6 / HIF44 carburetor. Has no vacuum take-off. Not water heated. This genuine Maniflow intake manifold is made just for performance. Tubular steel runners taper gently down to match a ported cylinder head. The small internal volume creates high port velocity with reduced turbulence. The result is a couple of horsepower gain over the aluminum counterpart. Ref: C-AHT781, C-AHT770M, C-AHT770.