Educate please

[LarrBeard]

Cylinder heads for L-134 engines are the subject of much myth and legend.

If you Google "L-134 Cylinder Head", pretty soon you will be in information overload.

The "Kaiser Supersonic" head gave a 7.1 compression ratio and was similar to the high altitude head. The "standard" was about 6.48, maybe 5 HP difference..

Industrial heads may or may not have had lower compression ratios depending on what the researcher can find on his particular head. Most have been planed and measurements are no longer original.

The M38 engine may have had the same compression ratio as an industrial engine, but it would take a comparison of the part number cast in the head to see if they are the same casting.

https://forums.g503.com/viewtopic.php?t=237948

SO, the answer is a firm "Could be, but...".