Re: Pick basics of new eliminator
 

The Q-Jet secondary blades protrude down .75" from the bottom of the base, so the spacer/restrictor needs to be at least that tall.

Holley 4150 rated at 500 cfm has 1.50' diameter throttle bores- all four.
A 600 cfm model is 1 9/16".

Holley makes an adapter intended to mount a Q-Jet or Thermo Quad on a manifold designed for Holley 4150 or 4160 (PN 17-6).

Maybe a 4 hole gasket underneath this adaptor is all that's needed for this test.