Cavalier Z24

I own a 1993 Z24 Coupe and Im currently looking
for alot of information. This has got alot of
different parts to it so here it goes.

1a. Im looking to add Horsepower to a stock Z24. I
want to replace the current 3 speed auto tranny
with a 4 speed auto tranny. Ive seen a 3rd gen with
a 4 speed. Would it be possible to switch to a
tranny with more gears?

1b. With the current air filter it sucks in air strictly
from a rear facing hood scoop which comes stock.
If i was to make a custom mesh grill and remove
the radiator shield would i gain or lose horsepower
switching to a cone?

2. Ive got a rough idle at times. Sometimes its
when i start up and others is when the cars already
warm. I havent checked anything as of right now
because i refuse to go into it blindly. What all
should i check besides carbon build up and spark
plugs?

3. Would it be beneficial to remove the insulation
that is attached to the hood? Will it help the car run
cooler?

4. What cars could i do a headlight and grill swap
from?

5. Im looking to add a more raw engine sound. A
rumble at least from the engine instead of just the
muffler. What would be best suited for this?


Im not looking for overall performance but at least
to make the car look cleaner, slicker. I know the
cars only standpoint is cosmetics.