I have a 95 SC in my driveway which had broken the balancer. So the bolt had snapped, and then the balancer broke leaving half of the hub on the crankshaft inside the timing cover - the balancer and pulley ended up getting stuck between the sway bar and the front brace on the subframe - the power wire to the starter was also shredded. Ended up having to take off the entire front part of the engine to get the hub off the shaft - and then drilling / EZ-out to get the remaining piece of the broken bolt out of the middle of the crankshaft. Total cost about $600 in labor cost, plus a new balancer, pulley, serpentine belt, support brace and starter wire. Oh yeah and expect to pay about $500 for the new BHJ balancer - you'll want to get the shorter bolts for the pulley also, or else it will wobble and break them off - the instructions dont say anything about it, but the stock bolts will bury themselves into the new balancer without fully seating the pulley. This applies to ANY year SC.
Then you still have the crappy brake system - if that fails, you're looking at a couple hundred for a new accumulator ball, or possibly a bad relay ( cheap fix ) .. but if the pressure switch fails, expect to pay a couple hundred, and then the easiest way to change that out is by using a hole saw on the inner fender, and using a ground down socket to remove it. If your pump motor fails, you're **** out of luck.
The SC from 94/95 got the Gen 4 Eaton M90 supercharger, plus 36 pound injectors. Its a decent upgrade, but dont expect a whole lot of power gains unless you spend a lot more money on a ported blower, or an AR kit. I wouldnt bother unless I had the forged internals and ported heads. By this time youve got over $5k invested into the car already if you want to start making some decent power.
The 94/95 also got the fully floating piston rods, slightly higher CR on stock pistons, and a windage tray. Plus the DIS system was fixed, so no worries there. Larger MAF, and the throttle body doesnt have that pointless coolant bypass through it. You'll also get the late model exhaust manifolds which flow much better than the early style - you wont see the upgraded driver side manifold until 1992, and the much improved passenger side came in 1994.
Every SC or NA V6 I have ever worked on for a blown HG had blown fire ring in the head gasket on the number 3 cylinder, passenger side rear .. wether its a cooling issue, detonation issue, or lack of exhaust flow, I am not sure .. but that is very common.
I picked up my 1994 SC after the previous owner managed to neglect the motor mounts until the oil pan rubbed on the subframe - drove it home and then the rod knock developed. Total cost for me to rebuild the engine was about $2200 including the ARP head studs, Rod bolts and a few other goodies, plus the BHJ balancer. At any rate, its almost not worth selling the car.
And the reason why most mechanics wont work on these cars - they are too stupid. Any job is going to take about twice as long but by the time you pull off the supercharger and air charge tubes, its just like any NA 3.8. Just dont be surprised if you get a quote of $500 to change the spark plugs.