[Formulajones]

Speaking of the 068, in my 400 it's baby smooth, no lope. It's a relatively small cam all things considered. I wouldn't even entertain the thought of using it in a 455. I'd go straight for something with no less than 230 @ .050 in an engine that large, like the RAIV cam these guys have suggested.
Even that cam in a 455 set up properly will idle pretty docile with only a slight hint at idle and produce plenty of vacuum as long as you have a little bit of compression.