Chrysler had all sorts of different single and dual shaft as they called them engines from I think about 1951 till about 1958 or so when they came out with B engine. I think that the main problem was that they were too expensive to build. Also I think that the main driver for the hemispherical and semi hemispherical combustion chamber designs was not performance/power but a way to allow the engine to be more tolerant of poor quality fuel. With that said I do think that they were all looking over the shoulders of one another to see what the other guys were doing with their designs. Chrysler did that too with their ball stud Hemi engine that was prototyped but never made it to production. The idea was to try to get some of the advantages of the 426 Hemi yet eliminate some of its disadvantages at the same time. To make a more versatile package to better compete with the Big Block Ford and Chevy. It's a shame that they didn't use that design.

What's funny about the poly angle 318 is how much stuff is exactly the same as on the later LA version. Even the cam core looks nearly identical. My friend Steve Demos had a guy who ran into that one time when he rebuilt his 318 and he couldn't get it to run. He had bought a new cam from the part store. Steve had him bring it in to check it out and it was the one for the Poly not the LA engine like he had. The valves are in a different order but everything else is the same.

 

Be bold, do a 351M.

 

Little chance I will build a 351m. 400 maybe. Probably will be a 460.