1958 Dodge
The Dodge hemi/poly has one of the smallest bore spacings (bore center to center distance) of just about any (or maybe any) American V8 ever. Viz:
Dodge hemi/poly: 4.1875 inches
Desoto hemi: 4.3125
Chrysler hemi/poly: 4.5625
Mopar A/LA: 4.46
Mopar B/RB: 4.80
Ford small block: 4.38
Chevy small block: 4.40