The seller may not know that this block is a standard block.
At least two things make the Australian Cleveland block different than its North American cousin. As a rule, Aussie Cleveland castings don’t have Ford North America casting numbers (as mentioned earlier), though it is believed some of the North American molds were shipped to Ford’s Geelong, Australia, foundry for those fi rst Aussie castings, which means there are some with North American Ford casting numbers cast in Australia. Another belief is Ford North America shipped discontinued Cleveland casting molds to Australia in 1974 when production ended here.
It may very well be an Aussie block. Look closely at the pic where it shows the D2AE-CA casting number the date code below it is 6D13 or April 13, 1976. I don't believe they were casting any 351C blocks in the US in 1976. Just a thought.
From what I've been able to gather about the 351Cs is that US production ended in 1974 and the casting molds may have been shipped to Australia, which is why the Ford US casting numbers were still used. The "M" blocks continued in production until 1982, and were never produced in Australia.
The 351C blocks that were produced in Australia should have a "GF" foundary mark on them, showing they were produced in Geelong, Australia.
I don't believe the standard blocks are any better or worse than the US produced ones. The ones with the "XE" part number are the higher nickel content blocks and were the NASCAR blocks that were shipped to the US from Australia. The "XE" blocks likely had the screw-in 'freeze' plugs.
This is the guy with the Mustang Junk Yard in N.C. Scotty Strickland. He says someone that knows them verified it. I have also read that the higher nickel content is a wives tale neither Mexico nor Australia are verified by Ford to be higher in Nickel. Would make it more difficult to machine.
The Casting mark near the oil sending unit tells whether U.S. or Aussie. But like stated the molds were shipped to Australia when production stopped here.
I turned down to complete 351 C engines with cranks rods and everything but no intakes or heads for $125.00 so not a deal.
Oh BTW, my .050" over with flat top pistons and cam with air on does not overheat in traffic or in the mountains in 80+ heat. With the baffle in the block and right thermostat no issues with stock radiator. Took across mount Pisgah on Tuesday and temp does not move.
I checked my AC today and still see bubbles in the sight window. Will leave the stop leak stuff in a few more days then dump and put DuraCool back in.
Based on the casting date code it's likely an Aussie block. I can't get a good look at the main caps which are another tell-tale sign. In the link below are pics of the Aussie block that I used for my build.