750 Vac

[Heo]

I bought a Holley 3310 750 vac today. It have a Moroso
"spacer" between the floatbowl and metering block on
primary side. Whats that? to get extra float bowl
 volume or what? havent dissasembled it yet

[machoneman]

Pic?

My only guess is an old and no longer sold spacer to increase the bowl's volume when running alcohol or, less likely, pure methanol. Either way, I'd check the jets, power valve if equipped and the air bleeds very carefully for their sizes....usually 30% larger when on alky.   

[Falcon67]

Adds volume - as noted, usually for alcohol.  Although, I've never heard or seen a 750 vacuum carb used on alcohol.  It's just not done.  Usually the minimum carb used is a 700 DP.  So it may be nothing more than some crutch the a previous owner thought necessary.  And probably wasn't.

[Heo]

Dissasembled the primary side i now. The spacer was filled with
"foam"like in a fuel cell. 89 black anodized jets. White slime in
 the fuelbowl like after metanol no corosion though.
 Air bleeds look big but i havent meassured them probably
some metanol experiment.Well it was more or less free when
i bougt a 390 block