Is it a fully assembled engine?
The heads will have screw in studs and cast valve spring cups. Part numbers include C30E, C4OE-B, C50E-A and C5OE-E. The first two have 49.2cc chambers and the second two have the 54.5cc chambers. They also have the slotted pushrod holes.
The blocks have thicker main bearing caps, Part #'s C30E-B, C4OE-B are 5 bolt blocks and the C5AE-E is a 6 bolt block. Blocks are sometimes marked with HP. A couple other numbers are C4OE-C and C4OE-F which I also believe are 5 bolt blocks, but not positive.
The crank will have 1M on it and may have a K stamped on the last counterweight. There should be a grind mark on the counterweight for the Brinell test.
The cam will be solid lifter mechanical, part number C3OZ-C and have a mark VE between the distributor gear and the forward journal (in front of the dist. gear).
The distributor will be a dual point with mechanical advance, part #'s C3OF-A or C5OF-B.
The exhaust manifolds are C3OZ-C for the right and C3OZ-B for the left. I also have a C5ZZ-B number, but don't know which side it's for, right maybe?
The 4V intake could be the same cast iron as a A code 289 with a C30Z-C or C3OZ-B number or an aluminum one with the numbers, C9OX-B, C9OZ-D, SFJD-F or C6AE-B.
The connecting rods should have a C3OZ-C or a C3AE number with 3/8" rod bolts and broached seats.
This information is all from the Ford High Performance Parts Identifier booklet by Robert Winkelman put out by Sunset Mustang and I'm not totally sure of it's accuracy as I don't personally have a hipo, but as no one has answered you yet, they might be able to clarify the information I've posted.