From his ebay listing:
This is a genuine vintage 351 Cleveland severe duty iron race block. These were originally intended for professional competition use in Grand National (NASCAR), Road Racing, Drag Racing (NHRA/IHRA/AHRA), and Off-Shore Boat Racing.
The part number is XE-192540. The “XE” stands for Experimental Engineering, a special division of Ford Motor Company that conducted research and development for many aspects of their racing enterprises.
No more than 350 of these blocks were ever made. Articles in the (Yellow) Ford Performance Book as well as the July, 1982 issue of Super Ford Magazine discuss the rugged nature of these blocks and their desirability.
In 1982, these blocks were issued to select race teams, privileged individuals and external development entities (i.e., Ernie Elliott, Neil Bonnet, Jody Ridley, Cale Yarborough, Bud Moore, Leonard Wood, Holman Moody, etc.).
This block is New Old Stock (NOS), still has the factory reddish glypthol paint, and has never had a piston in it. In fact, it is under-bore, like any NEW iron block before finish machining.
These blocks had the advantage of being manufactured more than 12 years after the first production 351C blocks, thus the XE block benefited from the wealth of data collected from Ford and associated racers, yielding an additional 40 LBS of material to dramatically improve the casting in every key area. Below is a list of the various engineering enhancements which contributed to the legendary rigidity of these distinctive castings.
(A) Cast from High Chrome Alloy to Provide Increased Strength for Improved Wear and Durability
(B) Machined To Close Tolerances
(C) 100% Inspected
(D) Increased Cylinder Wall Thickness for Precise Bore Dimensions
(E) Solid Oil Pan Rails
(F) Thick Non-Contoured Main Webbing
(G) Visible Casting Enhancement Between Freeze Plug Holes (Pillows)
(H) Select Nodular Iron 4-Bolt Main Caps on all five main saddles
(I) Weight: 200 LBS
(J) Semi-Finished Cylinder Bores To Allow Custom Finish Boring.
This XE block is compatible with widely available production and aftermarket 351C heads, intakes, and accessories. So, if you have been searching for a TRUE CLEVELAND BLOCK for your Musclecar, Pantera, or Hot Rod which can withstand extreme naturally aspirated horsepower levels, nitrous or boosted applications; look no further!!!