Charlie, 
          I have zero experience with the 570. Are the primaries smaller on it than a comparable Edelbrock 1405 ?. That could explain the better response  at lower rpm's with a small inch motor. That was always the hard part of trying to make a 600 anything work o a 272 or under 300 inch anything. I also don't have any experience with the Edelbrock 500 on anything. I can only relate to the 312-600 combo, and we know that works pretty well. c
           I suspect that a lot of our "opinions" on this subject arise from one example (like mine) and really aren't worth much on another combination. Example, My 65 GTO came with a Carter AFB. Same carb as the Edelbrock of today. As soon as I modified the car it became undriveable. swapped a 750 Holley on it and it was all better. Therefore I don't like AFB's / Edelbrocks. Well i was wrong!
  On the street at least they are very good. I had some bad luck with Holley 10-15 years ago and became set against them. They've cleaned up their act and now are very good again. Careful about  opinions!!

Outlaw: Check Lokar's cable setup for the AOD. It works very well, had one on my 408 Ranger P/U.  

Frank/Rebop

Bristol, In ( by Elkhart) 

ok, got you this time. Makes sense, lol. Geze how did I miss that the first time. Thanks Charlie!

Darrell Howard Whitefish, MT Outlaw 56 Ford F-100's

What I mean is when it comes time to get a carb for the 292, you can use the 500 off of the 272 to see how it does.  That way it takes some guessing out and you can decide on a 500 or 600 for the 292 more easily.
Regarding the throttle linkage, they offer conversion kits for various transmissions so they probably have something that will work for the AOD.



Lawrenceville, GA

Hey Charlie, I did tell Edelbrock Tech I would eventually want a medium build on the 272. They said anything below 300 would be fine with the 500 Thunder AVS I already have. I assumed anything above 300 would get the 600. Ted said he had experienced a flat spot on the the Edelbrock 600 he borrowed from a friend to test on his 272. My 272 will be the first truck I have running, so as long as I already have the 500, Im thinking I will try it on the 272. When it comes time to get another carb for my 292, I will maybe bump up to a 600 or 700. My other concern is in the 292, I have installed an AOD. I dont think the 500 Thunder AVS I have now is set up for the AOD Cable. Really not sure how all that works, but next carb I buy I will know more about what I need for the AOD cable hook up. If I understand correctly, some carburators come with the option of a throttle cable connect for an AOD and some dont?

Darrell Howard Whitefish, MT Outlaw 56 Ford F-100's

The Edelbrock 600 worked fine on my warm 292, other than that air valve problem, which you probably won't have.  Since you mentioned Thunder, I assume you mean the Thunder AVS, you absolutely should not have that problem because it is adjustable.
That said, if Edelbrock recommended the 500, that may be the one to go with.  Did you tell them your plans or just that it is 292ci?
Another thought is since you will already have a 500, you can try it on the 292 and see if you like it.  If you are satisfied with the performance then get another 500.



Lawrenceville, GA

Thanks Ted. If I plan on a mid range build for the 272 and a upper end range build for the 292, would you recommend 500 for the 272 and a 600 for the 292? I really like the idea of the Edelbrock becasue If I understand correctly, they are easier to tune and adjust than other options.Since I already have the 500 Thunder, Im thinking I should use it on the 272 and order a 600 for the 292? Not sure about the 600 based on your experience and the "flat spot". Wonder if a 500 or 700 would work for a hopped up 292.

I just called Edelbrock Tech. They recommend the 500 for anything below 300ci. The 272 won't be an issue. The 292 could be with a little modification. I think Im going to put the 500 on the 272 and order something bigger for the 292. Is should not take much modification to get the 292 above 300. 

Darrell Howard Whitefish, MT Outlaw 56 Ford F-100's

It’s difficult to go wrong with a vacuum secondary carb.  The secondaries on those are good at only opening the amount required by the engine.  Whereas a mechanical secondary carburetor is very rarely at the optimum sizing for an engine (either too big or too small), being oversized on a vacuum secondary carb will always insure the engine will get the amount of air it wants.

I run a 525cfm Road Demon Jr. on my own 272 now and it runs fine.  I’ve also run a 780 Holley on the same engine but drivability at low rpms was not as good as it seemed to be more sluggish right off of idle.  Full throttle performance was fine though with the vacuum secondaries.  I borrowed a friend’s 600 cfm Edelbrock carb and it had a noticeable flat spot or hesitation right off of idle compared to the 500 cfm Carter that I use to run on the same engine.

Lorena, Texas (South of Waco)

From what I have read (no actual experience), its pretty easy to over carburate a stock 272. The Edelbrock 500 Performer Series is leaning in the direction of "overkill", but it will work. If the stock engines future includes a more aggressive camshaft, bigger pistons, increased air flow with ram horns and increasing exhaust pipe and muffler diameter, I would hope the 272 would grow into the 500. Edelbrock also makes the 500 in the Thunder Series which I believe is the same as the Performer but includes adjustable secondaries. The Edelbrock 500 Thunder Series is the one I have brand new in the box which I had purchased several years ago for my 292. That 292 is going to get rebuilt one day and I am wondering if I should get a 600 for it and use the 500 in the 272. Any thoughts? Neither of these Y blocks is going to be for hot rodding, just daily drivers. I'm hoping to get good running engines with good gas mileage. Maybe the 500 series will be good for both?

Darrell Howard Whitefish, MT Outlaw 56 Ford F-100's

Here’s a picture of a Summit 750 cfm carb that was recently installed on a 303” Y with stock heads and iron intake.  It made 315 HP on the dyno and runs great in the car.  Only change to the carb was fattening up the secondary jetting three numbers.
 

Lorena, Texas (South of Waco)

I am using an Edelbrock 600 on my mildly modified 292 with zero issues, just bolted it on,set the pilot screws and idle speed.I have used the Summit carb both 600 and 750 CFM versions on a couple of other engines with really excellent results. I would buy either again,but would probably lean toward the Edelbrock just because I had such good results with Carter AFBs for so long.