Edelbrock makes the secondary rods for way cheaper that gm sells them for. Here are part numbers from www.summitracing.com:
EDL-1952 CK rods(pair) $6.99 (this rod is similiar to the DR)
EDL-1951 CE rods(pair) $6.99 (this one is richer than the CK)

EDL-1960 B-hanger $2.99 (they have several others for same price.)

These are made to fit right in the Rochester Q-jet

 

I've used the CK rods. So have several other people I know with QJets. And in every application they ran way rich, blowing all sorts of black smoke out on WOT. Almost all those were on mildly built 350s, so I can only imagine what it would do on a near stock 305.

And by the time you pay for handling charges through Summit, it costs the same amount anyway

 

So what exactly do these rods do and what kind of power do you guys get out of them?

 

Not really. If you buy several different rods and hangers at once for tuning purposes you pay a one time handling fee of about 6 bucks. Still way under the GM price. The CKs are just a bit rich on my application but I prefer to keep my timing up and not detonate. I just barely get a little smoke when I gun it and don't feel any loss of power relative to the AY rod that is a leaner rod. Summit also sells the AY rod and you can see below it is similiar to the specs of the DR if the CK is to much. I have also seen the rods for sale at a few online carburetor shops for a real resonable price.

CK 1345 1291 1154 927 527 527 527
AY 1352 1294 1165 932 567 567 567
DR 1323 1250 1093 882 746 581 570

They sit in the jets blocking the fuel. They are attached to the butterfly looking plates on top of the secondaries by a cam. When vacuum pulls those open it lifts the rods out of the jets letting the fuel out. The thicker the rod the less fuel that can come out. And the lower the hanger the latter the thin part of the rod comes up and vice versa. So thinner rods and higher hole on the hanger makes richer fuel delivery. But like Marc said, you don't want to go to thin for your application and be blowing smoke out the back of your car.

 

It only gained 1 MPH, but it was so much more responsive!