Machine shops that specialize in building custom crate engines deal with flathead V8 crate motors. These shops build them according to the customers specifications and polish, paint and ship each engine directly. Examples of machine shops include H&H Flatheads and Go-cat Flathead.
H&H Flatheads deals with vintage and antique engines. It sells completely customized Flathead motors which are all built to order.
Go-cat Flatheads is another vintage engine building company that has its engines all built by one person. Each engine receives a complete rebuild features parts such as full race cams, stain-less high-flow valves, aluminum timing gears and more, as of 2015.