Would my flex fuel injectors manage 12 psi and meth... Mods right now are 08 5.3l 214 224 601 610 lift cam circle d 3000 stall Sts turbo @8 psi and meth

 

I wouldn't think so... I'd opt for some 60's or at least some 42's.

 

I have some 60s but since its my dd... I guess I'll leave it as it is..

 

Might as well throw them on if you already have them... I have a 7lb. spring in my WG but have an adjustable boost controller inside the cab incase I need a little extra. Also, make sure your pump will support the extra fuel requirements as well.