Howdy; I would go with the ECG-D heads. The C/R will go up when you put 272 heads on a 292. Those heads have the 1.78" intake valves also. Remember to have them serviced first. If you can find a ECZ-B intake use it. They breathed a little better for a little better torque and it takes the "new" style big base carb. Also if you can find a 57 or later distributor that has the mechanical advance as well as the vacuum,try that. They work better. Let's just keep them running!

Pete.  I use 4% as the number for what the horsepower increase will be for each point of compression ratio increase.  After 11.0:1 CR, this number steadily decreases and at a certain point, there is actually a decrease in power output.  The amount of increase between 14:1 & 15:1 is minimal on many engines.

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Intake manifold casting numbers:

EBY-D intake - Teapot Holley four barrel on ’54 Merc (choke housing on intake)

ECB-B intake – Teapot Holley four barrel on  ’55 Ford (choke housing on intake)

ECZ-A intake – Teapot Holley four barrel on ’56 Ford (choke housing on carb)

ECZ-B intake – Holley model 4150/4160 4V carb on ’57 & up Ford & Mercury

Lorena, Texas (South of Waco)

Rick

  I would consider using the ECG D heads because you can get a higher compression ratio with them. For every point of increase of compression your engine will produce 11% more power. Install the larger intake valves and clean up the exhaust ports and add a true dual exhaust system. Although the S heads appear to be less "Shrouded" this is not significant with RPM below 5500 and valve lift of .450 inch or less.

  A good resourse is David Visard books on how to produce HP in street driven engines. Now is the time to choose a camshaft. Worry about the intake/carb at some future date. Pete

Rick, my 2 cents worth is use the S heads, there are basically 4 intakes, 2bbl stromberg/holley with 3 bolt mounting base, 57 on 2bbl 320 cfm holley intake with 4 bolt mounting base, small 4bbl teapot holley intake, casting # ends with A, 57 later 4 bbl holley squarebore intake, casting # ending with B. if using auto trans, keep in mind provision for K/D mechanism. You can check on John mummerts site in tech section on head casting numbers. regards bill.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

I am about to put a 292 together to put in my '55 Customline.

I have 3 sets of heads, but am unsure of which would be the best to use for a soon to be street driven automatic.

The casting numbers for the heads are ECG (no other lettering apart from 6020) - these came off an Aussie/Canadian '55 272, ECG D which were fitted to the standard 272 in my 55 (Californian car) and a set of ECG S heads which I acquired over the years of my collecting bits. I think these came from an Australian delivered F series truck - not sure of the vehicle size - it was used as a tow truck.

My quandary comes from the difference in combustion chamber shape of the ECG S heads. They are a simple D shape without the dimple in the combustion chamber around the spark plug of the other heads. They look like they would be a better chamber design than the others but they appear to have a bigger combustion chamber than the other heads. They don't seem to shroud the plug like the other heads. I would like to know what compression ratio these chambers are.

Here in Oz we don't have the availability of the better big valved heads fitted to American Y Blocks, so I will need to make use of one of these sets.

I would appreciate any thoughts.

Also I remember seeing an earlier post which listed all the casting numbers for Y Block inlet manifolds, but am unable to find it again. I have an early 4 barrel ECZ 9425 A and would like to know what it was fitted to originally. Any suggestions?

I hope you all had a happy and safe Holiday period.

Regards


Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!