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!!

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