I used the search function for a while last night and couldn’t turn up an answer to my question so here it goes. I’m working to tune a Dodge 325 that I did not build w/ an Offy dual quad intake like in the photo. Carbs are Carter AFB comp series clones. The rear carb supplies vacuum to a PCV valve using the PCV port, vacuum advance using the ported vacuum port, and lastly to the TH350 vacuum modulator using the brake booster port. All vacuum ports on the front carb are plugged. I’ve been tracking down a high idle that won’t come down with idle speed screw adjustment so starting with checking for vacuum leaks. I first pulled the carbs off to check operation of everything and noticed the previous owner used open style carb spacers. Since the carbs are square bore and the intake is square bore, could the open carb spacer between the two be causing any issues since now the plenum is “seeing” air+fuel from everywhere or is this a dumb question?? The intake is a divided single plane style.
I've never had any problems with dual quad hemi spacers. What I do know is on the dyno a 1" spacer always increases hp .
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