LT1 engine and T56 transmission were from a perfectly functional 95 Trans Am. At least I was able to re-sell the body.

As many of you know, I had to notch and box the cross member to clear the LT1 AC compressor. Then the motor simply bolted in using 3RD Gen engine brackets.

For exhaust I'm using SLP shorty headers and Y-pipe for a single cat 3RD Gen Firebird. These were the only ones I found that provided 1 3/4" primaries and true unrestricted 3" Y-pipe. In addition I got the catylitic converter adapter and a generic 3" slip fit cat. Before sending the headers off to be coated I installed a second O2 bung to the passenger side. This is where not to put it. It's too close to the starter and I had to shorten the O2 sensor. Should have angled it up.

The remainder of the exhaust is an Edlebrock single 3" cat-back with TEC muffler. That took some bending and cutting to get it to fit wright at the axle and around gas tank.
It seemed to be cheaper and easier to use Aeroquip braided stainless for the various hybrid lines than adapt existing or have crimped lines made up at the parts store. For the power steering I used the original molded hose from the resevoir to the pump, -6AN High pressure teflon and steel fittings for the pressure side and -8 AN and aluminum fittings for the return line.
The fuel line adapter fittings are from Pure Choice. These mate to -6 AN fitting for both the supply and return lines. I had to make a throttle cable using the throttle end from the 95 and the body end from the 87. JB Weld and a reinforcing piece of steel brake line hold the mess together. I fashioned a new ferrule for the peddle end of the cable out of 3/8 steel rod.

By utilizing the factory wire harness from the donor car I was able to maintain several features. My 87 firebird now has VATS security over starting, fuel pump and injectors. It also has the computer controlled staged operation of the duel electric fans as well as the AC compressor.
To mount the transmission, I purchased the spohn cross member and adjustable torque arm. I was able to utilize the 95's parking brake cables by making some simple L-brackets and welding them to the bottom of the car.
The car starts and runs now. The wiring needs to be shortened and routed and I haven't found a good home for the PCM. It may have to go where I put my power steer resevoir. Some brake lines might come in handy in the near future.