2004 redline, 91 octane, probably a devils own meth kit

1. 2.5 or 3 inch exhaust? (full, header and dp as well)
2. 60# or 80# injectors?
3. Is 2.8" Pulley safe for a DD that only has access to 91 octane?
4. Should I Invest in HPTuners ? Or should i just get the "pcm core charge" one which I assume gives me a PCM with a tune on it?
5. Shorter belt or adjustable tensioner/oversized tensioner pulley?

Assuming 91 octane, meth kit, 2.5 or 3" exhaust (assuming 3" is better) , good tune and 2.8" pulley (feel this is the safest option for me) will i be anywheres near 275-280 hp? or less,more?

Just checking out my options

 

2.5" exhaust
60# injectors
2.8" pulley is safe, especially if running meth
Tune - Best to find a reputable local tuner
Shorter belt is fine

270-280 CRANK hp is possible. To the wheels you will likely be 250ish.

 

ok first off there is plenty of info on here about what you are doing so search and secondly we have a dyno section that can give you an idea

Dyno Results - Cobalt SS Network