I remember the first design 427 Aluminum blocks, the ones which were all Aluminum without cylinder sleeves. They required a special honing process for which Sunnen produced honing pads to accommodate. The process honed back the Aluminum but left the Silicon in place (trick and back then a secretive alloy), so the cylinders would not wear as rapidly. They also required special rings and coated pistons (Iron coatings).
TRACO had a small number of Aluminum 327 blocks as well, which required the same process (actually they were procurred by Penske)
The one "weight" item which I remember as having the largest effect for engine life, was Carbon Fiber push rods, with your hand out and eyes closed, a person could carefully place one in your hand and you would not notice it. Back in those days, before overhead cams and without roller bearing lifters, the weight of the push rods was a large factor in cam lobe life. TRACO tried to get the manufacturer interested in producing Push Rods and or Wrist Pins, but at that time, the cost was prohibitive as the process required a large and very expensive Autoclave, high pressure, high temperature, controlled atmosphere mold press / oven. Today I'm sure the process would be (is) a fairly common process.
The Aluminum Cyl Heads were another PITA, requiring a special coating in the water jackets to keep the heat in, heating the heads and freezing the valve seats to replace them, then a special orbital valve seat grinder. Lots of time and work getting those ready.