I have heard that a stock map sensor is only good for about 17 lbs or so. Is this true? Or will it go higher?
Thanks for the help

 

you heard right. Its a 2 bar map. 1 bar reads vacuum and the other positive air pressure. Wont read past 17.5 lbs of boost. Wont read reliably past 16.5-17psi. Better off going with the 3 bar map. Its cheap and will work with most stand alone ECU's It reads air pressure more precisly due to the band being wider. Not significantly better but a must have for any high boost applications. You can buy a GM 3bar for about 90 bucks.