Reply to "big block vs small block"

Gary, I'm enthused about your project. A 4.5" stroke would yield 460 cubes. Cleveland heads, even the cast iron heads, can support that displacement. If headers aren't an issue (still hard for me to believe they aren't) then the motor mounts & bellhousing are the only pieces that makes this project anything other than a direct bolt-in. Many of the major part such as heads, distributors, water pumps, cams, oil pumps & oilpans are interchangeable between the 351C & 400.

An issue with some owners is the ability to keep everything under the engine screen. An intake that keeps everything low enough to do this would aid in making this swap more universally attractive. It would be tight, but achievable. The carburetor in the "L" Panteras sits on an EGR plate that is about an inch thick, about the difference in height between the 2 blocks. So I'll bet the oem 351C intake manifold with the typical intake adapter plates for the 400 would allow the carb & air filter (sans EGR plate) to sit tightly below the "L" engine screen.

Mark, since Gary Hall used the 4.25" crank in his Barney-mobile, that means the bore is 4.155", which is a 4.125" cylinder bored 0.030" over. (4.185" is a 4.125 cylinder bored 0.060" over)

Your friend on the PIBB, George