i'd guess the slayer has 3 emulsion holes per side, that's what the HR650 i have on my 318 is.
i think they are .031"..kinda large. but actually that carb (it's a 4150 though) runs great on a basically 318 stock motor, but it's a w200 and therfore 410 gears, 32" tires though is prob equivalent to a pass car with 3.55 gears.
i dropped the IFR's to .028" which is actually a little too lean but other than that it's all box stock and runs fine.

i wonder if the vacuum secondary is just a harder carb to tune..