That would be a lot of what vehicle the engine is in. For sure, the small block with Doug headers will be an orbit or two away easier than a BB with headers in a A-body.
But on the line of mechanics and ease of work'n on them, if we just look on top.......
the 383 intake swap is a marvel compared to the small block, as the 383 has no coolant through the intake, less bolts, and the gasket can be re-used right in place. Also, distributor swapping/tuning on the 383 is obviously easier up front than the rear. Water pump also, just 4 bolts and a small pump. Also, we could head down the block to the oil pump and oil pan ....