New 5.5:1 Cylinder Head Availability

[Bob Bidonde]

I have been running 5.5:1 and 6:1 compression ratio cylinder heads for many years successfully with Babbitt bearings. By the way, the bearing diameter determines the amount of bearing stress in the Babbitt due to cylinder combustion pressures and inertial forces.
It makes good business sense if the 5.5:1 head was discontinued because of the 6:1 head. The difference between them is only 3%.