[DeTomaso] Vacuum Advance - ported or full vacuum source

[dennis617 at aol.com]

Does anyone have an opinion on which source I should use for my vacuum advance on my Mallory Unilite distributor, full vacuum directly from the intake manifold or ported vacuum from the Holley 650 double pumper?  I have a mostly stock engine with an Edlebrock Performer intake manifold.  I have recieved conflicting information from Holley and Mallory, Holley claims that I should use the ported vacuum at the carb and Mallory said I should use full vacuum from the intake manifold.