Holley – easy to tune, good throttle response, lowest WOT power by far of the 3. Easy starting. Just weak in overall power though

Edelbrock – Best WOT power by far, poor throttle response (relatively) Runs much richer at idle to be happy. Used Oil analysis shows much more fuel dilution of oil with this carb then the holley to back up this thought (in addition to fuel smell). Just feels sloppy at mid range throttle settings; its more like on/off for around town driving.

Demon – disaster. Tried changing jets, power valves, squirters, timing, etc and never got it to run right. Took it apart and found all kinds of metal shavings and junk in it, and even after cleaning it out, never got it to be driveable….just terrible. I wont get another demon.

Specs of the car/engine:

56 Sunliner

292/ford-o-matic

Cam – mummert FY-270-3

Duration @.050 – 224/224

Lobe separation – 110 deg

Gross lift - .469/.469

Ignition – later style dist, pertronix, stock coil, initial timing ~15 deg (tried moving up and down); plugs about 4 mos old gapped to stock, wires about a year old.

Vaccuum at idle ~13-14" @500 rpm

Ive talked to Jegs (from whom I got the demon) and they have offered to exchange the demon for any other carb of my choice….so thus the point of this question. What carb would you chose knowing objectives and history? My thought right now is a #4160 holley 600, or morel likely a holley street avenger 570 (even though its dual inlet), although I have some concern over those being too big and losing some throttle response. I know some have recommended the holley truck avenger 470, but im not sure that would be a big enough jump over the 390? Also, anything weird about the truck carb – it specifically says not for use on v8’s.

Preference is for one with elec choke, vac secondaries, and single fuel inlet.

Also, Holley just released a series of carbs with non-adjustable floats (4160 series). Any thoughts on those (pros/cons?)?

THANK YOU in advance for taking the time to read this and for any thoughts/comments!

Holley's (or the Demon derivatives) have always worked out to my liking - tuning parts and knowhow has always been available....and over a 40 year period. If you are dead set against the Demons - Charlie's comments about the Avenger 570 sound right to me - and they have the big bowls and sight windows I believe.

Anything that has "non-adjustable bowls" must be for children.......   

Gary, on the 465, where did you hear that it was "made for the Y-Block?"  Id never heard that before, so Im curious as to the source.  i wonder what that means, anyways?

Also, with the 570 avenger, do the larger bowls fit ok with the stock coil loc and oil bath air filter?  ( have about a 1/2" spacer under the oil bath to give some more clearance, but the bowls on the dual inlet carbs are huuuugggee compared to the demon jr or holley 390; the oil bath has been gutted, but still looks/is dimensionally stock for appearance)

Thanks!

Steve, i too have had more expeirence and results with the holley 4bbl carbs, theres years of learning how to tune them to the parameters of the engines output, not merely adjusting float levels and air bleed screws. I guess its up to the individuals expeirence on any of the carbs. Holleys for me.

Really, that was from Holley direct?  very interesting.  Ive talked to the tech at Jegs, and used the holley on line carb selector, and both came up with the avenger 570.  Actually, the carb selector thingy came up with the 390 or the 570, but never the 465.  Looks like I should give them a call, huh?

I like the idea of the 465 due to its being physically smaller, and having a single inlet.  I do wish it had jettable secondaries, but oh well.  Im also concerned that the 465 wont flow enough at top end vs. the 570, but I guess there is no way to know between the 2 other than to try them.....

Gary, what kind of mods do you have on your car?  Did it require some jetting/power valve, etc adjustments?  Thanks!

At the beginning of this thread, you stated that the Holley lacked top end power.  Just a thought.  Are you sure the secondaries were opening?

Yeah, I saw that and noticed the linkage.  Looks like its time to call Holley....

Gary, the carb was opening all the way on the 390...

The more I read the more it seems that the poor throttle response of the eddy might be more due to the 500 cfm (and weak/poor signal) than it being an eddy/carter style?

Ill post up what Holley has to say once i get a chance to call them.

Thanks!!!

That makes sense, but I have one of the original mummert AL intakes, so no heat passage for the choke tube.  Id have to get the electric choke conversion kit for about $50 or so.  No big deal.

Talked to holley tech.  Soon as he heard 56 ford he said the 465.  He didnt really seem to care/want to hear about cam specs, rear end, etc....just automatically went to that carb.  Not sure if that means its the perfect fit, or that he just didnt want to deal with me!?!?!  Right now, Im inclined to try the 465, hoping it gets me the best of both worlds between the 390 throttle response and the 500 WOT power.  Like most, i have a hard time accepting that bigger isnt always better!

As for the sycamore show, we wont be there.  We are going to AZ for 2 weeks this sunday to visit parents, so.....

Where is St Germain, anyways?  We live about 20 miles south of the WI border, almost due south of lake geneva.  There are some good shows/cruise nights around here....let me know if you ever want to make the trip or want info about car shows, etc.  We have a GREAT car club in northern illinois - lots of activity, no dues, no politics, no elected officials.  Its pretty amazing actually.  About 240 members or so.....let me know if you want to meet up sometime!

**EDIT**  HOLY CRAP!  I just looked on google maps... you are WAAAYYY up there!  That is a long drive to sycamore!  Stay safe!

Marv - Ive tuned the eddy with different springs & rods, and you are right, it helped a ton.  It is still sloppy, however, and gets poor mileage compared to the holley 390 (on the order of 10-12 mpg). 

I figure since i have a credit from Jegs, Ill probably try the 465, put on electric choke, and see how it goes.  I havent really heard anyone with a reason to go to the avenger 570 thus far, except for the guy at jegs.....

Gary, you say you have a mild cam.  Do you happen to know the specs?  Everyone (articles, etc) refer to "mild" cams, but i dont have a point of reference as to what specs are mild vs. aggressive? 

Thanks to all for the input and patience.  In case you havent figured it out yet, I tend to overanalyze things....

Im trying to get this decided in the next fvew days so I can send the demon back to Jegs before we go on vacation to AZ for 2 weeks, so hopefully I can come home to my shiny new carb!

I do want to say THANKS to everyone who chimed in.  I honestly cant tell you how much I appreciate your thoughts and input; thanks again!!!!!

To be fair John, I may have misquoted him.  He certainly said i may have to mess with the secondary springs to control timing of secondary opening, but he may have only been referring to it in relation to the weight of the car, cam peak rpm range, etc.  I may have misheard him relating it back to manifold vacuum.

Thanks!