What Pump do you have?
 

Year Trans. HP@RPM Ft-Lbs@RPM CPL# Comments
1994 Manual 175hp @ 2500rpm 420tq @1500rpm 1816 pre 1/1/94 without catalytic converter

1994 Manual 175hp @ 2500rpm 420tq @ 1500rpm 1550 post 1/1/94 with catalytic converter

1994 Auto 160hp @ 2500rpm 400tq@ 1500rpm 1815 pre 1/1/94 without catalytic converter

1994 Auto 160hp @ 2500rpm 400tq @ 1500rpm 1549 post 1/1/94 with catalytic converter

1995 Manual 175hp @ 2500rpm 420tq @ 1500rpm 1550 with catalytic converter

1995 Auto 160hp @ 2500rpm 400tq @ 1500rpm 1549 pre 1/1/95

1995 Auto 160hp @ 2500rpm 400tq @ 1500rpm 1968 post 1/1/95

1996 Manual 215hp @ 2600rpm 440tq @ 1600rpm 2023 49 state pre 1/1/96 12.5 degrees BTC

1996 Manual 215hp @ 2600rpm 440tq @ 1600rpm 2175 49 state post 1/1/96 13.5 degrees BTC

1996 Auto 180hp @ 2500rpm 420tq @ 1500rpm 2022 49 state pre 1/1/96

1996 Auto 180hp @ 2500rpm 420tq @ 1500rpm 2174 49 State post 1/1/96

1996 Both 180hp @ 2500rpm 420tq @ 1500rpm 1863 California with EGR

1997 Manual 215hp @ 2600rpm 440tq @ 1600rpm 2175 49 State OBD-II

1997 Auto 180hp @ 2500rpm 420tq @ 1500rpm 2174 49 State OBD-II

1997 Both 180hp @ 2500rpm 420tq @ 1500rpm 1863 California with EGR OBD-II

1998 Manual 215hp @ 2600rpm 440tq @ 1600rpm 2175 49 State OBD-II before Jan 1, 1998

1998 Auto 180hp @ 2500rpm 420tq @ 1500rpm 2174 49 State OBD-II before Jan 1, 1998

1998 Both 180hp @ 2500rpm 420tq @ 1500rpm 1863 California with EGR,OBD-II before Jan , 1998

Credit to Haleybilt

what does the 4 digit number after the rpm rating mean?

They are CPL numbers (Critical Parts List)