[csx700?]

i'll give you some clues:
1) the heads will have screw in rocker arm studs and cast in valve spring retaining bosses, slotted pushrod guide holes ( also available on all pre '66 heads). part numbers to look for are C30E, C40E, C50E.
2) the block ( 5 bolt (pre '65) or 6 bolt ) will have thicker main caps, the rest of the block is identicle to a normal production block. the blocks went thru various tests to become suitable for the hipo application.
3) the crank balancer is thicker and usually is a C30E or C50E part number. C8ZE balancer is not an original hipo part.
4) the camshaft will be of a solid lifter design and the rocker arms will be adjustable.
5) timing chain is thinner and has a "hatchet" shaped plate (balancer) behind the crank timing gear.
these are some of the easy things to look for when comparing engines, hope this helps...........john