1994 Chevrolet Blazer 200k miles v6 Vortec Not Accelerating?

My blazer will not accelerate well at all. It will slowly and I mean slowly accelerate. I could probably smoke it off the line by foot. It sputters, stalls, backfires, has gas smell, and reaches only 3 thousand rpms on the dash. It seems to eat a gallon of gas per mile. And is just killing me in repair bills. This is what I have replaced from what mechanics say will conquer this problem. I have replaced the whole exhaust. High flow cat and walker muffler. New EGR. New AC Delco wires w/ autolite double platinum plugs(APP25). Yesterday I replaced the spider injectors, plenum gasket, and fuel pressure regulator. They all seem puzzled or don't wanna touch the thing. After a number of diagnostics, I've heard different solutions.(bad: ignition coil, ignition module, fuel pump, and timing chain jump.) If anyone knows how to fix or had this stalling, no accelertion slash backfiring problem with gas smell, please respond. I seem to be getting broke and annoyed by this problem and these mechanics.

You have 2 big fuel lines inside the intake. One that supplies fuel to the fuel injector unit and one that returns unneeded fuel to the fuel tank. If the drivers side of the intake is clean, one of those lines is cracked. It'll also show up as #1, #3 and/or #5 spark plugs wet & greasy with fuel. I replaced those lines to repair my '92 one time.

I was about to look into that when I noticed all my plug wires are melting by the sparkplug. I also noticed there is no heatshield underneath the engine. So I think this might be the problem. I'm need to change the wires to something more sturdy. That or rig a new heat shield. Got any suggestions on both?