85 s10 blazer 2.8 v6 problems

Ok my brother has a 85 blazer that won't go over 6 to 7 mph now it was running fine. He was told that is was just a fuel filter so we put a new one on. I am thinking that it might be the fuel pump but can not find any diagrams or location of the pump. Need help to figure out if it is the fuel pump of not and where it is located.

The '85 came only carburated. The fuel pump is mechanical and is located on the block. I don't remember, but I think its on the drivers side front of the engine. If its leaking, don't drive it like that. If its not leaking gas externally, it throwing gas inside the crankcase. Take a good look and let us know what is happening.