Generally,
EDG = 383 (Mercury)
EDH = 410 (Edsel)
EDJ = 430 (Mercury / Lincoln)
although some parts interchange among engines. For example, the intake numbers, although technically coded for Mercury, are the same as commonly found on 1958 Lincoln engines- at the least the ones I have.
The pistons do appear to be Edsel which shared the same MEL block but was bored slightly smaller than the 430.
Of note are the date codes. These are parts from an early 58 MEL engine, with castings dated August 1957 and the final engine assembly 8/22/1957. The intake is dated 8/20/1957, the cylinder heads are dated 8/21/1957; they may not be original to the engine based on the engine's final assembly date but maybe they are. I have heard that the 410 was only produced for a few months and was dropped by January 1958, and was only available in the Corsair and Citation Edsels. There was also supposedly a large Edsel marketing campaign and hype in the Fall of 1957 so perhaps they were rushing to build cars as fast as possible which might explain date codes appearing within a couple days of each other.
If you consult the 1958 Lincoln service/repair manual as well as the 1958 factory-issued service bulletins for Merc/Linc you will find that the factory implemented a lot of modifications and changes on the early 1958 engines, and not all at once. I'm not sure if Edsel issued service bulletins or not. From what I have been able to find for Merc/Linc 430s:
camshaft changed to a smoother idle one on 11/11/1957
Mercury 383 head #5750063 (smaller intake valves) was implemented starting between 1/9/1958 and 1/20/1958
block height was increased 0.020" to lower compression on 2/17/1958
Intake valve seat angles changed from 30 degrees to 45 degrees in early 1959 (per 2-4-59 Service Bulletin).
There were changes to carburetion too, and Lincoln went from 4-barrel Holley in 1958 to 4-barrel Carter for 1959 then back to a 2-barrel Holley for 1960.
This engine could be very desireable for someone doing an Edsel restoration or otherwise interested in an early 1958 engine with higher compression and larger valves. Less knowledgeable buyers might be getting more than they have bargained for.
Date coding per Linc/Merc Service Bulletin #8 (convention is "XY-Z" = "Year Month - Day")
See the following link for posted chart:
viewtopic.php?f=29&t=14&start=40
If you want more info, I can put you in touch with an Edsel person I know who could probably shed more light on this topic.