You can DD with drag radials. Buy Nittos as they are the best in dry and the best in wet. I use them all year round and still pull 1.8 60ft times at the track.
You best mods first off are gears. They will get the car out of the hole. Exhaust will add great sound but minimal power. Offroad H pipe and a cat-back will make the car sound great!!! Headers are a waste for a stock engine. I spent an afternoon in the garage and they were worthless....no noticeabe gain. Underdrive pullies are cheap, and yes they will make a difference. Installed those, and I could see a difference by the time I got to my neighbors mail box.
Hmm, that seems to point to exhaust and intake work. So what's wrong with porting the lower intake, it's the biggest restriction on the motor, and would be cheaper than buying an aftermarket intake. I run a stock ported intake and I'm making 400+ rwhp.
porting a stock intake is only worth it if you do the heads and atleast 1.7s to boot.. just like anything, you put a 70mm tb on a car with stock MAF sensor and stock intake, you wont see much difference