Hello everyone, blazerforum newbie here, I will try to explain in detail what's going on.

I was on the highway doing 65, I decided to go past a slower moving vehicle, so I pressed the pedal to the floor to get going and a few seconds later while I'm accelerating I heard a loud "bang" come from the front of the blazer and it was immediately followed by a constant banging and loss of power. As of right now, if I turn the blazer on, it will immediately start banging and I have to keep my foot on the throttle to keep the rpm's up or the engine will die. There is no smoke coming from anywhere, there are no leaks at all, no funny smells either. I'm truly lost and confused, my blazer only has 167,000 on it, it's a 2wd, 4.3 v6. Please help.

 

I would first climb under the front of it and check for any obvious damage to the engine block.
If you don't see any obvious damage pull all of the plugs and see if any of them have damage.
If you still don't see any obvious damage to the plugs then rent a compression tester from a parts store and check compression on all cylinders. This will give you an idea if there is major damage inside the engine.

 

Sounds like engines knocking. Can you make a short video and upload it to youtube?