Tim, et al.,
The 1952-54 passenger car side mount bosses were cast into the 1954 261 factory replacement blocks, at least in the three such blocks that I have acquired over the years. However, the bosses were not always drilled and tapped, as two of the blocks had solid bosses. I drilled and tapped the bosses in 1958 in order to put one of the block in my 1953 210 sedan. As one of the other blocks went into a 1951 coupe, there was no need to tap the bosses. Has anyone ever figured out just how many different Stovebolt blocks-heads-engine combinations were produced. If I ever retire that would be an interesting endeavor; but I need to clean up my shop, basement, wood shop first.
Hoyt