The good news about the 454 is that it’s virtually a direct swap for the 350. We reused the engine mounts from the small-block, though lining them up on the frame was inexplicably more difficult with the 454. The big-block bolted right up to the TH350 trans because the bellhousing bolt pattern is the same, and the B&M torque converter was double-drilled to accept the flywheel bolt pattern. We sort of butchered the throttle linkage to make it work (not too proudly, though), and the small-block radiator and hoses even lined up. We used the small-block fan and shroud after swapping to a shorter Flex-A-Lite fan spacer, but the shroud is uncomfortably close to the lower pulley because we used a long water pump setup (brackets were more expensive for the short pump). A real big-block shroud and a beefier radiator would be better.