Hi can anyone tell me how or if you can identify Dport manifold and heads without pulling a motor down? Also if the heads definitely look like a D as opposed to oval on the intake side then they are D port heads that is correct? Only have seen some for sale and they look like Dports but the swears there standard oval port heads, funny that he listed them with manifold and the Manifold was bought in three days.

The Inlet manifold on an Oval Port has a raised section in the casting just forward of the carb, about the size of 3 X $1 coins in a pile.  (looks like where a temp sender would be drilled and tapped), a D port manidold has no lump.
 
The D port Heads have FORD in an oval, cast into the section between the exhaust ports, Oval Port heads have FoMoCo in a square in the same place.
 
The Timing chest on an Oval port has the fan offset to the left, the D port fan is central

gtv6capri
The Timing chest on an Oval port has the fan offset to the left, the D port fan is central

Does that mean a different timing cover is needed if fitting a D port setup?

The front covers are interchangeable. Be careful when fitting a different (later) timing gear to the oval port motor, the front plate stiffener might need a small amount of grinding to miss.