Everyone trots that out as if it were some sort of valid test, but they were too cheap and/or lazy to get a couple of strip kits to calibrate the carbs, they said the engine was running 10.9:1 a/f ratio, i.e. way too rich. If Offy was spending AD money with that rag, you can bet it wouldn't have even been included without a re-jetting. To the OP, the low Offy manifold can only run Holleys sideways NOT inline.