It is like comparing a FYB DIST to a SBF DIST, it will fit but will it? I know the driven gear count is different between a LYB and FYB.

Here is a FleaBay photo(s) of an FAB 12370-A (1954-56 FORD 239-272) -

https://www.ebay.com/p/1523067050

Again, hold onto the take-out DIST as one day you or another owner may want numbers correct.

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"BTW, the engine was running very hot. Think I finally figured out why ----zero vacuum advance so it's running retarded (lugging along on initial timing of 14 degrees). Can't verify until I fix the VC."

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It's been a ton of years since I adjusted a Load-O-Matic strub and I'm not at home to look for information.  As I recall,  the calibration is accomplished by the size of the office in the venturi of the carb., the spark control valve and the 2 springs in the strib that control the rate and amount of advance. If you find a Ford VC that has a similar diameter diaphragm, similar rod, it would more than likely be close. Or as stated above, would get you by until you make the change for the dual advance strib.. Hope this helps, good luck............

64F100 57FAIRLANE500

Thanks all for the thoughts and ideas guys!

I'm planning on abandoning the original '54's dizzy (original to me) for the '57 dizzy once the intermediate shaft arrives in 3-4 weeks. I believe the '57's dizzy will provide superior street performance since it includes both vacuum and centrifugal advance. Simultaneously I'll also modify the original Holley 2140 "Teapot" to provide full vacuum to the '57 dizzy (Ted's "how to article" is posted on this site) using the original intake manifold. I also have a '57 intake that will be installed with a Edelbrock AVS2 500cfm if the modified Teapot approach fails. 

Meanwhile back to the '54 dizzy. I do plan on replacing the VC and holding on to it until someone needs it. The "ebay" offering referenced above is for a 55 Truck which might work. I sent the seller a message asking for dimensions. But due to it's intended application (heavy truck?) it may pull less vacuum advance which is certainly better than none. 

While on the related subject of ignition timing what do you guys think of following timing targets for a street 4300lb sled, stock 317ci + Hydramatic, for cruising freeways @ 2800rpm (65MPH):

Initial : 14 degrees
Vacuum Advance: 12 degrees total, beginning @ 7"Hg, max @ 15"Hg
Centrifugal Advance: 22 degrees beginning @ 2100rpm, max @ 4,400rpm

"Meanwhile back to the '54 dizzy. I do plan on replacing the VC and holding on to it until someone needs it. The "ebay" offering referenced above is for a 55 Truck which might work. I sent the seller a message asking for dimensions. But due to it's intended application (heavy truck?) it may pull less vacuum advance which is certainly better than none."

The FAB 12370-A is for FYB PASS CAR. It may have a TRUCK APPLICATION.



You have to be careful of seller's on Flea-Bay. Most have no idea of what they are selling.

As for the DIST itself, if not using, consider just leaving alone and if selling post the canister as defective. Someone will want that DIST, preferably undisturbed.

As for the curve on the 1957 368 DUAL ADVANCE, maybe start with the OEM SPECS as the 368 was fairly well pumped up and go up from there if necessary.

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Looking at your centrifugal timing question, do you mean distributor degrees or crank degrees? Same question for RPM?  If you mean 22* crankshaft (11* strib) + 14* initial timing would be 36* total at the crank which would be a place to start. Centrifugal advancing generally starts coming in at around 1100 +/- engine RPM.  I don't recall seeing a 57 stock dual advance Y-block strib with these numbers. 

64F100 57FAIRLANE500

My timing numbers above are referenced to crankshaft degrees (good question).

In hindsight I probably should have left the 57's 368ci' dizzy centrifugal spring alone. As you guys probably know, changing this dizzy's spring is a B. While the dizzy was being "refreshed" i.e., completely torn down and rebuilt, I asked the fellow to place a new and slightly stiffer spring into it. After assembly the Sun revealed it begins @ 2100 rpm and all in 22 crank degrees by 4400 rpm.  Instead of biting the bullet and taking another hour to change the spring again, I opted to install and test it "as-is" in the car. I suspect I'll regret this decision (D, I knew it!) but so goes this game.       

Centrifugal cuts in a lot sooner than you think. If not, there would be a stumble before ported vacuum cuts in. That is why it is important to set initial @ curb idle unless the curve has been modified.

Look @ this TUNE-UP CHART - 1957 FORD 312


You had your distributor recursed on a DIST MACHINE hopefully and they gave you a curve chart?

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If that's the case, that is, starts to advance at 2100 engine RPM's, you will have a rather lazy performing car. In my experience, most all the Y-block dual advance stribs are somewhat similar in curve. Yes, they can and sometimes need to be adjusted on a machine but most of the time with all else being good, initial timing can get the car performing well enough without spark knock. I would say if the shop still has the strib, I would opt to have it put back the way it was. No advance until 2100 RPM is going to be very sluggish. Look at the last post from KULTULZ, note the specs for the cintrifugal adance curve and you will see where it should be. That is rather typical for most STOCK Ford V8's of the day.  BTW, where are you located?

64F100 57FAIRLANE500

Your comments make sense and thanks for including the detailed data specs.

The spec states centrifugal all in by 2000 rpm. So mine is way off then. Unfortunately I didn't get a curve ---the mechanic gave me a few data points he wrote down ---Begins at 2100rpm, all in 22 degrees/4,400rpm, 10 degrees/ 2800rpm, 18 degrees/3600. At least I can extrapolate the curve.

Since this car will primarily frequent freeways at 2800 rpm, my total timing should hopefully be 12 initial  + 14 vacuum + 10 centrifugal = 36 degrees. I suspected this new curve would not be optimal but decided to roll with it and see what happened (yes it's my first Y block rodeo). From what I'm reading above I'll leave a lot of performance on the table and money at CA tax (gas?) pumps.  

How much advance can a 317 accept when cruising at light load? For lean fuel economy can it take 42-44 degrees without detonating?