try putting a thin, 3/8"-1/2" or so, phenolic spacer between the carb and intake. this will mitigate fuel percolation problems which are common on cars with aluminum intakes and especially common with aluminum intakes and holley carbs for some reason. or instead of a phenolic spacer use the thick paper.cardboard spacer from an 86 model ford pickup with the HO 351 4v engine, NAPA part number FPG60390. this spacer will also require 2 regular paper gaskets as well but any standard 4 hole gasket will work fine. i'm using this one on my 351w with e'brock intake and road demon carb and it works fine, i've also used it on several other combos in the past. it's probably not quite as good as the phenolic spacer but loads better than none at all. if you're using the stock ford aluminum spacer as well use this should go between the spacer and the carb, you may need slightly longer carb mounting studs with both the stock spacer and this one as well.