P185 pump is what we want
P185 was available in 97-99 chevy Medium Duty trucks with a 6.5 diesel.
most "P" series saganaw pumps will put out between 3 and 5 gpm depending on flow mod and pump shaft speed
keep in mind there are different stile P pumps there is the p132 and the p185
the 132 is the every day run of the mill p then the 185 has the larger ring and rotor (it pumps more oil) which is like the "1400 pump" from PSC
there is only one true way to tell the difference between a P132 and a P185 and that is to compare the ring and rotor (the P185 ring is .200" taller)
*** most re builders seem to use the lower flow pumps in applications that were factory high flow ***
top pic is 185 bottom is 132
Hydroboost brakes "P" style saginaw pump with attached reservoir (1980 Chevy K30 4x4 1-ton with 350c.i. and Hydroboost brakes)