I modified a stock intake to have a 500 Holly two bbl with the barrels parrlell with the engine. works fine. I milled the carb mount off the manifold, and spray welded a 3/8 steel plate with the Holley configuration, to the manifold. Did it in 1978 and that manifold is still on my 66 Valiant, with a 170 running high 12's with a fogger system.