I know that a 12:1 FMU is what every one is told to use. Will a 10:1 FMU work or is the extra 2psi that important? I only plan on running around 6psi.

If you are sticking with stock injectors, you need to stay with a 12:1 FMU. If you don't, you risk going lean under boost and possibly blowing your engine up.

Thanks for the quick response.

Actually, you only will need betwwen 90-95PSI at 6 pounds of boost with stock injectors. Even an 8:1 FMU would technically work but most people go with the 12:1 for 2 reasons:
-faster ramp-up pressure for safer part throttle boosting
-extra insurance against leaning out under full boost WOT pulls

A 12:1 will put you around 110-120PSI depending on your fuel systems condition (with stock FPR) which is more than you need of course. Just make sure to use Walbro 255lph GSS-342 'high pressure' fuel pump with the FMU setup or you wont be able to sustain such high fuel pressures. When you start to exceed 110PSI with the Walbro...you REALLY start losing fuel volume (i.e; you'll lean out the mixture and risk blowing the motor) so be careful how high your pressure is reaching.