A couple things. The car will drive with the bad harmonic balancer, but it will make a similiar noise to what you are saying. I changed all pulleys, belts and water pump before discovering that the balancer was making the noise. I don't think it is the type of part you want to get from a junkyard for that old of a vehicle. Beware of ones made in China. I have read many horror stories of them failing very soon after installation. I think your blower problem is the blower motor. Common in pontiacs. You're lucky it made it this far.