Ditch as much cast iron pieces off that 472 as you can. Use a B/RB aluminum water pump housing, aluminum heads, aluminum intake, aluminum water pump, aluminum radiator, ditch the power steering for an aluminum manual chuck, remove your heater box, all the carpeting, spare tire, jack, trunk mat, and the afore mentioned back seat. Fix rear quarter windows in place, remove rear window regulators. This will lighten it up a lot more. I wouldent pull out window regulators in the front doors which would probably be a small nicety to have. This is gonna save you a lot more weight than carving on the thin unibody sheetmetal with a plasma cutter and possibly weakening the crap out of it. The only fiberglass parts that will save you a bit of weight over steel will be "race glass" parts like fenders. However, these will not hold up for over the road use in the long haul and will tend to start cracking as they are very thin for light weight on a drag race only car. A 4 pin light weight lift off hood would be ok as well as fiberglass bumper and aluminum bumper brackets.
