O.K Where do I start.
Firstly, welcome to the forums, you'll see that they're the greatest thing since sliced bread.
BLOCK: The Windsor has an 8.2 inch deck height measured from the crank centerline.The Cleveland is 9.2 inches and with heads on it appears a wider V whilst still being 90 degrees.
CRANK: Cleveland cranks have larger main bearing journals and conrod jornals(2.749 v2.49)for the main and 2.311 v 2.200 on the conrods(please dont quote me on the windsor figures, they're pretty close I think?).
CONRODS: The Windsor has 5.155 length conrods(Is that right anyone?) and using 5/16"rod bolts and the cleveland uses 5.78" ones and 3/8 bolts.
HEADS: The cleveland heads are huge square things that are much wider and weigh a ton and the valve arrangement is offset(canted)ie the valves are not directly in line with each other compared to the windsor and using pedestal type individual non adjustable rockers. Cleveland intake and exhaust ports are larger than any windsor(especially the 4V Clevo). Other tell tale differences are the fuel pump of the windsor is located on the drivers side and the clevo on the passenger. Water neck from the radiator top hose goes directly into the block next to the distributor. The windsors one goes directly into the intake manifold. Obviously the Cleveland is much heavier. Hope this helps you. Cheers