Colorado is the most correct.

FE engines had a large circular bellhousing that was not used on any other Ford engine family. FE was the first big block, cid was 352,360,390,406,410,427,428. FEs can be easily identified as an FE by the large size of the engine, the intake manifold being almost half way under the valve cover, and the deep skirted block that was a follow on from the Y block (292,312)

Clevelands and modifieds are small block engines. They have canted valves like the 429/460 but are still a small block. Yes the M's had the same bolt pattern as the 460 and they make great truck engines, espcially the 400M. Clevelands and Modifieds use nearly identical heads, if you need a set of heads for a Cleveland an M is a good place to get a set with hardened seats and 2V ports. Samey same for all of them, except for a bump in the exhuast port in later Ms.

Clevelands, Modifieds and Windsors all use the same bore spacing. That means they all have the same distance between the centers of the bores. That also means that the heads will physically bolt onto any block from the 260 to the 400M in those families. The 260/289/302 used 7/16 head bolts where the 351/400s ALL used 1/2 head bolts, so you need to open up the bolt holes to put a 289 head on a 400M. But there is really no reason to do that because those heads wont feed a 400ci engine. but you can put the C and M heads on a 289/302 as they have the 4" bore so the valves will fit, and that is worth doing.

It sounds like we need to expand the differnces in C and W to include ALL late Ford engines. Thankfully you guys dont ask too many flathead or Y block questions.

Its the size of the engine, not the displacement that denote big block and small block. If you really want to have it proven that a Cleveland and a Windsor are about the same size, I have a digital camera and a tape to measure them. Modifieds are slightly taller and wider but still a small block. its a bonus that the 460 trans bolts up, especially in trucks.