New Motor, New Problems

This is my first time on the board and I'm getting pretty desperate with my Tahoe so any advice is very welcome. My Tahoe is a 1996 model with a recently installed 350 with a hotter cam. The power specs are about 310hp and 375 ft/lbs. torque. The motor has not run right since we put it in. It feels like it has much less power than the stock 350 did and is not responsive at all. It feels like it is choking for gas and wants to die at low rpms, but it had a full gas tank and was empty after only 150 miles so it is sucking the gas down. I was running it on supreme gas too. I don't know if this is the fuel pump or fuel pressure regulator. Also I think there is a short somewhere because the battery won't hold a charge. Last but not least it got stuck in 4 hi and when it finally shifted out there was a loud bang and now there is a leak from the tranny or transfer case but can't tell which. Any ideas on any of these problems is greatly appreciated. Thanks.

Time to trade out, you need professional on site help with this. The modified engine requires fine tuning based on the mods, I assume this is still a fuel injected engine? The engine changes can cause havoc on the pcm trying to figure out how to control fuel mixture and such. What are the cam specs compared to stock, is it installed straight up? What else has been done, what is the idle vacuum?