My 94 gt is making this strange almost squeak/chirp sound while under load at low rpms. Especially noticable going up hills. The car bogs down going up hill also. I bought the car used and just recently put on a set of underdrive pulleys and a 75mm throttle body. This sound seemed to exist before these mods but its gotten worse since them. Oil level is good. Temp is good, oil pressure seems to surge/pulse at idle. But goes back to normal after I touch the gas. This does not happen when the car is at higher rpm. Timing needs to be fine tuned but I'm not sure what's going on here. I hunted down all vaccum leaks I could find with smoke. New spark plugs and wires, new ignition coil and rotor. It doesnt sound like a knock. I'm hoping this is just some kind of pulley squeaking and not a bearing inside the engine. Car has 150k miles on it so anything is possible. Anyway here's the link to the video. Thanks in advance.