HELP 91 4runner w/ stupid problem

Well 1st off, Hello I just joined this forum in desperate need of help. I bought a 91 4runner V6 with 197k miles 8 months ago and have been on and off fighting with it( I have never won). Everytime I try to fix a problem I throw money at it and the problem still prevails. I should of left this truck where it stood, but hey how hard could it be to fix this problem right? Ha! Anyway here goes. When accelerating under load like clockwork the engine bogs down between 2700 rpm and 3000 rpm( complete loss of power)if I back off the accelerator it will catch and continue to climb slowly. I can get up to 80 on the highway but it's back down to 75-65 on inclines( no passing power). I've gotten real good at shifting before 3000rpm and balancing the throttle on the highway. I have changed the plugs, distributer, plug wires, rotor, coil, air mass sensor, fuel filter, air filter, and oxygen sensor I even drove it with no cat just a straight pipe. I took it toyota for a 1hour diagnostic and it took them 2 1/2 hours to give me no solid answer just some slim possibilties. oh yeah I have a slight feeling it's the ignition system cause the smell of unburned gas is there when it bogged. if you put it in 2nd gear - 5th and floor it it will not go pass the 3000 rpm line just sit there and bog like it's goverened. well thanks for any help or insight you could provide.