Walbro Fuel pump - part number

[beast14]

I have this pump:

Walbro GSL 392
10504-1

is this the 255lph???..........

how much psi can it handle???

 

[si.c R]

Mine arrived today and its a GSS 341 :?

 

[buffalobilla]

it can take upto 500bhp, not sure on psi :?