how do you know it was a 5.0? what do you have done to your car? stock 5.0s are slow but not that slow. heres the power ratings:

94-95
hp:215 @4200rpm and torque:285 @3400rpm.

92-93
hp:205 @4200rpm and torque:285 275 @3000rpm

91 and earlier
hp:225 @4200rpm and torque:285 300 @3200rpm