I don't have much experience with the 400, but the 390 in my '75 has some serious balls compared to this thing. Mind you, it's a high compression motor out of a '67 Fairlane GTA.
I mean by sheer design. The Ford 400 was the first 400 cube small block. They beat Chevy out of the gate. Also, Ford used a superior Cleveland style canted valve head. They were used in literally everything Ford made except smaller cars from 1970 to 1982.
A lot of people mistakenly call them big blocks, but they are not. They share the same bellhousing pattern as the 460, but they have the same head bolt pattern and bore spacing as all the Windsor small blocks. The Windsor cranks will even fit in the block, but of course will not work, because the mains are way too small. However, the Ford boys have been strokin 351W engines with the 4" 400 cranks for a long time. They have serious untapped power potential.
