First of all hello back. The two engines (454) will be pretty much the same. There is no timing belt. It’s a chain and gears. Cam can be changed in car. Pull fan shroud ( probably the only advantage of the wasted space under the hood) and possibly the radiator. But my question is why are you doing that? Please post reasons for cam change. That’s not an easy job. Intake manifold, valve covers, rockers and lifters, water pump,harmonic balancer, possibly the oil pan, timing cover all have to come off. And then there is the little stuff.