Weight savings

also remove the heater, wipers/motor, a fiberglass bumper with light brackets (i assume you meant not femders or doors by no fiberglass), carpet padding, if currently power steering, go manual, headers, aluminum heads, aluminum intake, aluminum water pump (and housing if big block), aluminum radiator, monoleaf or coilover rear suspension.

there's surely more, but beyond that, you'd get into cutting up the car and i don't think that's really necessary