Drop in fuel pressure???

1998 Gt, 2000 engine, SQ trim, #42 inj., 255 lph high pressure (gss-342)

going into boost it drops from 40-36 psi, this is only taking it up to 3500 rpm or so, haven't gone any further.

now, I'm getting different opinions but it might be best to do both.

1. drop tank again and open up basket a little more, already drilled a few 5/8's holes

2. not worry about the tank and add a in-line pump

so, what do I do? also, what's the best 255 in-line to go with?

thanks,
Wes

ttt