You know what irks me? Edelbrock hardly infers or states to use step up springs for half of idle vacuum.  
I only know about it from my Holley style carbs and listening hard for a mention of it in this video.  
So today I asked the internet and VOILA, it referred to "The Half Vacuum Rule".    I have a copy of the older style Performer Series Carburetor book here and it never mentions the "rule".
My basic Chevy small block runs 17" of vacuum and I have some silver springs in my 650 AVS2, but I'm going to do some testing with pink and orange springs.  Fun stuff this test and tune!

Your videos are truly valuable! Here in Italy, there aren’t many skilled technicians for this type of carburetor, but thanks to your tutorials, I’ve learned a lot and managed to tune my AVS2!

Very helpful!
I bought a used SBC 305 for my C10. It’s oil smells like gas the exhaust ports have black powder on them and plugs are very badly fouled. The seller included the engines 1406 600CFM that needed an accelerator pump replacement. After taking the carb apart I see dark short step up springs. I’m suspecting that has much to do with the problem and he was using an electric fuel pump without a presser regulator.
I used your amazon affiliate to order the rebuild kit, springs and accelerator pump.
Once I get the engine running with my mechanical fuel pump will look into ordering a fuel presser regulator kit from you.

Thanks  Man,...your words helped me alot!!...67 Plymouth Belvedere 440 with 800cfm Eldelbrock.

4:20 You're saying that we need more timing for todays fuel, but everything I've heard and read says todays fuel burns *faster*, which would mean less timing.  I asked the Google AI and it referenced Engine Builder Magazine and told me todays fuel burns slower, as you said, but when I read the referenced article, it actually said that modern fuel burns faster.  Also, Walter at The GT350 Garage  says modern fuel burns faster.  In fact, he advocates for less total timing with an efficient combustion chamber and high compression.

Another great video my Edelbrock 2065 dual quad set up arrived 2 weeks ago I ordered it 8 months ago the metering rod's were bouncing at idle 300 duration cam I put in the blue springs and they stay down at idle, I'm sure there is more tuning to be done idles great in gear plugs are tan colored and it's a frickin blast when I put the pedal to the metal in my 68 Camaro good guys in Puyallup is 2 weeks away I'll be there keep the videos coming

With regard to removing the spring/piston/rod and just running on the jet, besides running extra rich and being unable to install a sufficiently small jet, you'd be creating an internal vacuum leak since the piston is no longer there.  Sure, the piston doesn't have rings and doesn't really "seal" to its bore, but it does provide an impingement.  After all, if it didn't, it wouldn't be pulled down by vacuum in the first place.  I suppose the piston could be installed by itself, but that would do nothing for the rich mixture.

Very, very helpful explained simply. Used cater AFB's for years they were always easy to work on. I have used edelbrock AVS2's and they are pretty dam good. Thank you for your information Buddy, Frank

Hey Boss, love your educational videos, if recall our conversation a couple months ago, installed the in the tank EFI Bosch fuel pump, having 6an fuel lines & Holley regulator for my 91 Jeep YJ with the 383 stroker and the AVS2 500 cfm...Runs absolutely perfect now. Will begin tinkering with the fuel mileage now since the Fast AFR was also installed as well.Keep up the awesome information, it's appreciated.  👍

So I bought a cheap Amazon kit changed out couple gaskets and I messed with my idle screw once I put it all back together and put it on. I think it’s a really high idle and now I’m getting that ticking noise. Thank you for the clarity love your videos and clear knowledge.

Thanks from Japan🎉

Great Video, Thanks for taking the time to upload all these Videos.

I just came across your videos bc im at the limit of my patience with my new engine build, and you may have provided the help i was in search of. 350 SB, 30 over, flat tops. I made the mistake of putting a Thumper series Comp cam in it with 107 degrees separation, 492-502 lift 282-288 duration. Flat tappet. VERY low vacuum!  Its a teeth rattling lick and I've tuned and timed till im ready to set fire to it bc it won't idle or run worth a darn. Only thing I haven't tried is the springs. We'll see. Great video

Why didnt you measure the id and od.  ?

i am guilty never think about them after they goes in the first time. great tips

Always Great videos!! Thanks

Thanks I have a 355 engine with a 650 avs2 edlebrock carb. I just now put in a pink spring , the 7 spring and wow . Great 👍

Excellent!

You explained it very good
Thanks I’m more confident going into this now👍👍👍

Awesome video man, great information and easy to follow. I’m new to carbs and about to rebuild a 1406 for my 350 k5. Thank you so much for what you do. And for the tip about the 12 degrees before TDC.