Alum. head question.

[GMH454]

What sort of alloy heads are you talking about. The 074 and later ZL-1 style, plus other racing style heads are probably not suited to a tripower unless you were contemplating running it with a manual mechanical likage instead of vacuum.
The earlier style heads have the "normal exhaust " and would be better. ....actually a small port set up with the edelbrock small port style heads might be a sweet street combo, but not have the visual you are after.
If you get it wrong and it drives like a pig, the style of set up your talking about is not cheap experience.