There was some previous talk in this thread about the PROMAX metering block not having the vacuum port.. and that is what I'm using... about 8 years ago, they (Promax) told me that I didn't need the port for the vacuum advance. They knew my driving -- some street/highway and road course HPDE/HSAX autocross racing... so, yes, it has lots of part-throttle, only occasional flat-out WOT. The car runs great -- and also now with a new SB stroker if still runs great (SB six-pack recently professionally rebuilt).

When I was ordering the Promax setup (base plates, etc, etc), they wanted to know all my specs, etc. They said they would make the metering block to better match my overall setup.... I'm an easy sell.

But... I'm curious if I should put the original OE/Holley metering block WITH the vacuum port back on and see how it would run.

Interesting thread.

(Maybe the Quick-Fuel metering block WITH the vacuum port would have been the better choice?)

Last edited by Mopar Mitch; 02/16/21 03:31 PM.
Mopar Mitch "Road racers and autocrossers go in deeper and come out harder!"... and rain never stops us from having fun with our cars... in fact, it makes us better drivers! Check out MOPAR ACTION MAGAZINE, August 2006 issue for feature article and specs on my autocross T/A!