The venturi's in the 4776 Holley 600 DP are so small would think it might be allright for off road on a mild 360. The 4776 Holley DP is the only one with (4) 1-9/16" dia. butterflies. Holley 4777 650cfm through 4780 800cfm all have (4) 1-11/16" dia. butterflies, and the 4781 850 cfm has (4) 1-3/4" dia. butterflies. Dominators have (4) 2" dia. butterflies. If the plastic whistle baffles are in both bowls it should handle the steep angles and fuel slosh. Somehwere on the web there was write up on carb performance off-road and thought the quadrajet came out on top iirc, but it does not fit the AMC spreadbore intake iirc. Might get a Performer Intake and try it with the 600 cfm 4776 first before buying a vacuum secondary.