Nitrous Question

my father has a 1989 mustang with gt 40 heads, upper and lower intake, and the matching mass air and throttle body,
HE also has a 75 shot of nitrous , Dry system, and is wanting to change to a 100-125 shot.. what is the opinions on that ? Will the motor hold up ? and is there anything he has to do besides just change the pill ? or is it that simple as just changing the pill ? no tune or anything else ?
thank you in advance

ok, thank you, the car had it on when he bought it, so he is not sure what system it is, just knows its the dry system,. The guy told him it was a 75 shot, and that it had a new fuel pump, but he don't remember the size of pump.
I have a 92 gt, Mine is a 306 with the entire gt 40 upper half of motor.and 410 gears
if its that simple , I may put a 100 shot on mine because His 75 shot makes a pretty big difference.
when he don't spray , I beat him by 2-3 cars and when he does spray , he beats me by 2 cars
so no dyno tune is required after I do this, correct ?

is there any way to tell the fuel pump has enough pressure without taking the fuel pump out of the gas tank and seeing which one it is ? ex . put a fuel pressure guage on and seeing what the pressure is ? IF so , what should the fuel pressure be at ??