Demon blow thru question.

what some guys do is use the dual vacuum diaphram from the late 70's that had a vacuum retard feature as well. you leave off the vacuum retard hose, and just use the advance part of the unit. when you get into boost, you now have a boost retard unit for cheap.
 
Since you run timing low, lock the mechanical section at 18 deg. Then like rbohm said, use the vacuum advance for driving and to keep EGT's down. But no, you don't have to run one. Must just lock out the timing and don't mess with it anymore than that.
Make sure to take that thing straight to the dyno
 
Not saying demons are no good or anything, but you really should take it apart and clean it good. My buddy bought one, (and have heard of ALOT of people having the same thing), and we took it apart and it was FULL of aluminum chips! Take it apart and clean them out first!!! Since, it has run very nicely.
 
Yea, it had some chips in the secondary bowls.

Actually it ran great before with the demon I modded out so I dont expect any problems with this actual blow thru set up. If you have a boost referenced regulator that takes care of most of the problems. I have everything I need to swap it to F.I. if it gives me real problems down the road though.