Holley SD intake will take all the low end torque away, I tried it several different ways on my 383. In the great intake dyno test it was down something like 30ft lbs @3000rpm to a dp4b, imagine how bad it was way down low.

when it was still NA and carb'ed, my car had a lot more grunt from an idle with the stock intake and 3.23's then it did with the SD and 3.91's.