Sorry, I do not have my Ford books available, I am working off memory.
First, bore sizes. 4.050 could be a 360, 390, or a 410.
The crank for the above engines has a stroke of about 3.5, 3.78, or 3.98.
The next standard bore size is 4.130, I think. With the 3.78 crank, you get a 406. The 3.98 crank gives you a 428.
The 427 block has a bore of 4.230, I think. Used with the 3.78 crank, you get a 427.
Some 406 and 427 blocks had cross bolted main caps on 2, 3, 4 main caps.
Some of these blocks also had provisions for a direct oil passage to the crankshaft, and were called side oilers blocks.
And if you get really lucky, you may come across a 427 OHC FE Ford block.
I'm no FE expert but FE's are tough to ID since Ford used one casting # for several different size blocks...352/360/390/406 and 428 IIRC. The only way to confirm what you have is to measure the bore and stroke.
the heads have brass tags on them the intake is a ford aluminum,the bore is right and the valve covers are ford factory and all numbers match.the head tags say it`s a shelby cobra gt500 so i`ll be buying crank rods and pistons for whatever,the bore job turns out to be,going into a 1969 f100.