I had them both installed for about 18mths on my '96 XJ, seat of the pants felt like an increase in low down torque (manifold) and a bit more top end (throttle body). No dyno proof, sorry. Lots of info on 'Google'.
It was a straight forward bolt up, including power steering pump.
I originally purchased for an upcoming stroker build, not happening now, my XJ is dead
Asking $350.
Will come with the fuel rail, injectors, TPS, IAC & MAP sensors.
PH: 0408 336650 (Ruffy) or PM here