If you've got a 6.5 on hand, try it, it might not mind it. Test drive will tell. Again, potato, potawto, neither PV means anything unless you happen to press the gas pedal down into those vacuum levels and the primary main circuit is functioning (load/flow/rpm dependent) at the time.
They have a small affect, yes, and a greater affect on transition if open more, sorta like transfer slots exposed below the throttle plates... (keep this in mind when thinking about this: within the idle/transition circuit, holes or slots above the throttle plate are air bleeds, and below the throttle plate is air:fuel feed) but more open secondary idle mixture screws or transfer slots below the plates would also have a greater affect on increased and unnecessary fuel usage at idle. Like other traditional Holley 4 barrels, a very small amount of secondary fuel is administered out of constant idle discharge ports that should have an approximate diameter of 0.020" (much bigger than that has a negative increased unnecessary fuel administering at idle) below the secondary transfer slots at idle in order that the fuel in the secondary bowl doesn't go stale if the back barrels rarely get opened... as well as keeping the secondary transfer slots ready with air:fuel to go into action when called upon by secondary opening. If there's an issue when the secondaries open... you either install a stiffer spring to open them later, or you modify how much transition air:fuel is getting to those transfer slots... because again, there's no pump shot out back, so pretty much any speedy secondary opening can be adjusted for with the right amount of secondary transition with idle feed and bleed sizing...
Reply With Quote
Connect With Us