Not that it matters, but the Summit carb looks much more like a Holley 4010 / 4011 than an Autolite 4100.


Lawrenceville, GA

The Ford/Autolite (flattops) carbs are simply getting much harder to find and especially those that haven’t been rebuilt several times.  The 1.08" series are even harder to find than the 1.12" series.  Those carbs tend to get damaged on the rebuilds by over-tightening some of the fasteners and this makes these carbs a tuning nightmare.  Prices on good used units are now exceeding the price of brand new carbs so it becomes questionable to sink that kind of money into a fifty plus year old carburetor.
 
The new Summit carbs shares internal design features with the older Ford/Autolite design and uses Holley replacement parts for the jets, needle seats, accelerator diaphragm, and secondary parts.  Being available in both 600 cfm and 750 cfm varieties makes them well suited for a wide range of applications.
 

Lorena, Texas (South of Waco)

Yes, the Ford  Autolite 1.08 that Ted included in his random carb tests on his 312 + test mule, some time back, scored better than several of the larger carbs in the tests. It was likely originally off of an early 289 Mustang.  The newer Holley 465 was even somewhat better & very near the top of the 16 carbs tested. All this was documented in a Y-Blk Magazine article..  However, note that the Autolite 1.12 did not test near as well.


Paul

why doesn't anybody use an autolite 108 off a 289, they look ariginal, they're super simple, small size, and very easy to find and rebuild!

 lincoln/merc. y-blocks &mel's                                                               bucyrus, ohio.

Ive always had good luck with swap meet holleys on daily driven small cube non-y-block cars-. List number 4548 i belive is the 450cfm '70 ford replacement carb (D0... part number) Add a secondary metering block for the hell of it and center hung bowls for the full 4150 conversion. I cant wait for the pair of them with velocity stacks on a offy crossram to sit ontop of my 302 GM mutt!   On my Y i'm going stock -1273 holley for a stockish look. Some wierd learning on these since they use secondary power valves but otherwise it should be a sweet setup just like the '57 t-bird had.  My other option is the centerpiece of my kitchen island is a edelbrock y-block tripower with 3 stomberg 97's.

This is my opinion, I have had Carter and Edelbrocks for over 50 years and not once have I had to fix a leak, buy a piece to fix one, or adjust anything on one after the first install. The instructions for jet sizing is very good and no gas will leak doing a jet change. I have had minimal experience with Holley's so I won't open Pandora"s box with that one.

  Vic Correnti

I am totally satisfied with the 600 cfm Edlebrock on the 1964 292 in my car.  Was good right out of the box and has performed  perfectly for 2 or 3 yrs.  Prior to that carb, I was pretty much constantly frustrated with the Holley 4bbl and a new replacement of that Holley-----neither ever ran right for very long despite taking it to a carb shop for rebuild, and then replacement.  After many years of messing with it, I picked up the Edlebrock on sale and life has been good since. 
BTW, in my case the air cleaner I used for the Holleys fits fine on the Edlebrock.

This is one of the hardest things to advise on.  If you have the money or can borrow, try both.  It is simply the only way you can know which will suit you best.

If that is not an option, then err on going a little bigger than you think you need, which makes the 500 the good choice.  You could also look into a 465 Holley.





Lawrenceville, GA

The original Ford and Merc 4V teapots are in the 400 cfm range give or take a little.  As a general rule, those carbs are on the small side for 292/312 engines if going for passing gear performance.  For daily driver purposes, they do the job admirably.
 
When it comes to choosing another carburetor, sizing is not necessarily the major consideration.  The brand (Holley, Carter, Edelbrock, Demon, Quick Fuel, Summit, etc) and how well they atomize the fuel will many times overshadow the cfm rating.  I have very good results using the Summit 750 carbs on 300 cubic inch engines but part of that success falls back on the annular discharge nozzles in those carbs which do an extremely good job of atomizing the fuel in the lower rpm ranges.

Lorena, Texas (South of Waco)

1956 ford Teapot 370 cfms- Lincoln Teapart 390 cfms as discussed earlier.


-Gary Burnette-