The following were on the engine at Flint when it was painted - block, heads, intake, pan, balancer, water pump (hub and shaft masked with a cardboard tube), valve covers, exhaust manifolds, bellhousing, lower flywheel cover, clutch fork, and distributor (was masked with a coffee can). Everything else was installed on the engine dress line at St. Louis.
There are lots of "Chevy Engine Orange" rattle-can paints out there (Dupli-Color, VHT, Seymour, etc.); any of them will do the job - I prefer VHT, as it has much higher temperature resistance than the others and lasts very nicely. Clean the engine thoroughly first with lacquer thinner to get the grease and oil off of the surface so the paint will adhere and stay there.
The Flint paint job was pretty sloppy - 280 engines per hour came through that little booth, and coverage varied widely.