Auto Parts: Tranny Problem, oldsmobile cutlass supreme, oldsmobile cutlass

Question
Hi there. I have a 1985 Oldsmobile Cutlass Supreme with a 455 Rocket engine swap matched up to a TH-400 tranny. Lately I have noticed that while driving if I push down on the gas pedal to pass someone or get up to speed it makes this weird grinding noise. Keep in mind this is not a constant thing, only when I'm accelerating harder than normal and usually in second or third gear. Now I was told that the tranny was rebuilt with only about 1500 miles on it, but now I am beginning to seriously doubt it ever being rebuilt. Also, while doing a Wide Open Throttle run my car makes a loud screeching noise for about a second or two and it usually occurs when in higher rpms. Any help or advice would be greatly appreciated.

Answer
    I'm thinking that the torque converter might be bad.  A lot of times folks will rebuild a transmission and not replace the torque converter; this is a serious mistake.  You need to let someone who knows transmissions (but not a transmission shop, they'll just sell you a new one) listen to it and maybe drive it.  They will be able to tell you.  The high RPM screeching, if it comes from under the hood, could be the fan clutch.  Check it out soon, "cause if it's bad it will come apart and shoot the fan through the radiator.