Just asking.....educate me please! 
I have NPI heads just like the NPI 96-98 Mustang on my t-bird (go figure huh?). If I get PI heads from a 99+ Mustang that will bring my compression to 10:1 correct? I have a 6 psi supercharger from Allen and want to go with PI heads and get the Allen REV-1 PI runner manifold. My question is how can I compensate (get safer compression) for the compression with forced induction if I get the PI heads?
I have NPI heads just like the NPI 96-98 Mustang on my t-bird (go figure huh?). If I get PI heads from a 99+ Mustang that will bring my compression to 10:1 correct? I have a 6 psi supercharger from Allen and want to go with PI heads and get the Allen REV-1 PI runner manifold. My question is how can I compensate (get safer compression) for the compression with forced induction if I get the PI heads?