I have to agree with Larry on this one, I started reading this thread and thought, "Hmmm... everyone is assuming its a Chevy 350, I wonder if it's a Pontiac 350 in there?"
All the "restore it to stock" or "make it your own" comments aside, that Pontiac 350 is a perfectly good motor. They can be built up just like any other Pontiac. They seem to do well with small valve, small chamber heads. Those 7H1 heads should have 1.94" intake and 1.77" exhaust valves and 80cc chambers, they can be worked over to perform very well. There's plenty of potential in that engine if you do a little work to it. It has a lot more power producing potential than the 301 that was installed at the factory. (Not knocking the 301, just stating a fact.)
As for your rear end, the GM33 code won't help much, there is a code stamped into the passenger side axle tube that will give us a clue. Or, if its not readable, put your rear up on jack stands, put the car in neutral and spin the rear tires. Count the number of times the driveshaft spins per one turn of the tire (a white paint pen helps to mark the driveshaft for this). If it spins 2.5 times, you have 2.56:1 gears, 2 and 3/4 turns would be 2.73:1, if it spins 3 times, you have 3.08:1 gears, and so on. When you turn one tire, if the other spins the same direction, you have a positraction differential in good health. If they spin opposite directions you have an open rear end or your positraction clutches are worn out.
Hope this helps. Post up all your other questions and we'll all do our best to help you!
Matt
