My line of thought is that any gains could only be measured in tenths of a second reduction in ET but not by the seat of your pants . And any chassis compromises would make the car less enjoyable to drive .
Aluminum intake and heads
Aluminum 4sp OD if its a manual
Manual steering and brakes
Lighter wheels and skinnier tires
3.55 gears
You would notice a big difference in all those changes. Much more than spending hrs whittling away 3 lbs here and 4 lbs there.