302 w/truck avenger. Flat spot, the final verdict...

[kayakersteve]

That is what Holley says

They apparently determined it can not supply enough air for a V8. Call tech line and ask for Ricky!

 

[Moon's74]

Change the vacuum secondary spring to a lighter one. You will get all the air you need. The biggest problem is the primaries alone are too small and flow too little and the secondary spring is too stiff and they come in too late. Just change the spring to get the secondaries open sooner. 470 is plenty big, you just need all 4 barrels to get there.

This is not the cure for the hesitation, however. SEE ABOVE.