Here's the deal on the block patterns. Remember Ford is involved in all this.
International had this diesel engine they made (the 6.9, 7.3 idi) that had an international bellhousing pattern. Ford decided they wanted to make a deal and use this engine in their pickups. Ford did make an adapter to mount to the back of the international engine, they all have it. But what did Ford do? They made an adapter from a international pattern to another oddball pattern they made up. Why did they do this? I don't know. But they had to re-tool the c6 castings and get ZF to make a oddball casting just for the oddball diesel pattern they came up with.
Why didn't they make the adapter to use a standard Ford big block pattern? Don't know.
International had this diesel engine they made (the 6.9, 7.3 idi) that had an international bellhousing pattern. Ford decided they wanted to make a deal and use this engine in their pickups. Ford did make an adapter to mount to the back of the international engine, they all have it. But what did Ford do? They made an adapter from a international pattern to another oddball pattern they made up. Why did they do this? I don't know. But they had to re-tool the c6 castings and get ZF to make a oddball casting just for the oddball diesel pattern they came up with.
Why didn't they make the adapter to use a standard Ford big block pattern? Don't know.