From what I understand, the cams are all the same for the 2.0 and the 2.3. If you are trying to find more torque and power, swapping for a 2.3 or a 2.5 might give you better results. The EFI intakes are very nice, and the later model exhaust manifolds, factory even, are nicer than what was installed in yours (and mine).
You likey have a carburetor. Have you considered going with a Holley-Weber 2bbl? Or a 4-bbl adapter?(way too much for normal use...) Factory muffler is pretty restrictive, and just replacing with an aftermarket can also improve torque.
If you want a normal cam and a bit more power & efficiency, get an 89-94 roller follower cam and followers. Less friction, and more power.
tom