I have the same car and love it. Also have the IPD bars and BillyHDs + poly bushing mix and IPD HD rear springs.

I think the 91 LH3 motor came with an M cam not the T cam. Although, I'm not positive as I swapped mine out early for a Enem V15, and the original cam is mixed in with other M cams now... But I've never heard of a LH3 motor getting a T cam. ???

The only way I can think to check the stock cam in the motor is to try and mic it while still installed.

There are two things you can do immediately to boost the motor's performance.

First is swap the cam, and be sure to get an adjustable cam gear to bring back the low end power. An "A" cam is cheap and OK, plus it will run without the cam timing advanced OK. But a "VX" is better. I hear a "B" cam is good but have not tried it. I have tried "A", VX", "V15" and RSI "Stage 1". V15 is best (but expensive delivered from Sweden) followed by the VX. The RSI cam is garbage (all high end with terrible idle). Any of these cams (except the RSI) should be better than the "T"... either the turbo specific "T" cam or the low rpm/high torque "T" cam.

Second, since your car is manual tranny, swap to an electric fan system. Taking the fan load off the motor really helps low rpm spool up time. This makes pulling away from a stop light much more pleasant. And when driving at speed the fan is off and there is less load... A few hp gain. More of a better feel upgrade than a real power increase. Full info on this conversion is on TurboBricks. I did the 940 fan in a 240 Turbo shroud conversion. The real key is to have a in fluid temp sensor either in the hose (Saab part) or upgrade the radiator. AND you have to upgrade to a 100amp alternator, plus I recommend Dave Barton's adjustable voltage regulator set at an increased voltage... Electric fan conversion costs a bit of cash, but it is a nice upgrade. There's a reason 940's went to electric fan. It is all laid out on TB.

The cat back exhaust upgrade will ad a few HP also. One less muffler and bigger pipes. The parts are all stock turbo exhaust except for the IPD transition pipe.

And have your injectors cleaned/balanced. Worth the $90.

There's not much you can do to upgrade the ignition, beside putting in good 8mm silicone wires.

A K&N air filter helps. And permanently closing that warm air flap can help, but it then takes longer to warm up the motor in Winter.

I have read where the LH3 ECU is "chipable", i.e. you can modify the ignition curve by changing the chip, but I'm hesitant to go down that road...

The bigger 960 throttle body is another "upgrade", but I don't know if the LH3 throttle control valve will work with it.

That is all the mods I can think of without pulling the head.

FYI: I did port/polish a 531 head, including intake gasket match, and run it in my 91 245 now. Had Knox Motorsports do a 3-position valve job and shim the springs to the VX cam... Quite a power difference, but it wasn't cheap.

Have fun!