tranny or torque convertor slipping?

Hello- I have a 67 2 wheel drive Ford with a nicely built 460 running an honest 450-500 hp. The transmission was rebuilt, but fairly stock. Im currenly running the stock convertor (have a hughs convertor on the shelf waiting to go in). The tranny does have a full manual valve body. Rear end is 3.54 with a Detroit locker. Tires are approx 26" tall and 10" wide. Under normal driving I can shift ithrough the gears with no problem. However, under heavy acceleration (from a dead stop) somethings not right. If I were to start from a dead stop with the gas to the floor the truck takes off and feels like its spinning, but when looking at the black marks the truck only leaves marks for about the first foot. Even after I shift into second it feels like theres no load. The engine easily revs to 6K. Im thinking that now that I have the locker and lower gears (truck originally had 4.10 and one wheel peel) the tranny is either slipping or the torque convertor cant handle the load. I havent smelled anything burning and the tranny fluid isnt burnt. Could it be possible that the problem is in the torque convertor? Ive read that C6s are pretty strong transmissions and can handle a lot of power. Any ideas would be helpful.

truck-collector wrote:Hello- I have a 67 2 wheel drive Ford with a nicely built 460 running an honest 450-500 hp. The transmission was rebuilt, but fairly stock. Im currenly running the stock convertor (have a hughs convertor on the shelf waiting to go in). The tranny does have a full manual valve body. Rear end is 3.54 with a Detroit locker. Tires are approx 26" tall and 10" wide. Under normal driving I can shift ithrough the gears with no problem. However, under heavy acceleration (from a dead stop) somethings not right. If I were to start from a dead stop with the gas to the floor the truck takes off and feels like its spinning, but when looking at the black marks the truck only leaves marks for about the first foot. Even after I shift into second it feels like theres no load. The engine easily revs to 6K. Im thinking that now that I have the locker and lower gears (truck originally had 4.10 and one wheel peel) the tranny is either slipping or the torque convertor cant handle the load. I havent smelled anything burning and the tranny fluid isnt burnt. Could it be possible that the problem is in the torque convertor? Ive read that C6s are pretty strong transmissions and can handle a lot of power. Any ideas would be helpful.

i'd say the converter if the fluid look ok.a trans dont slip without burning fluid and a loose converter will "cook"the fluid after a while.pull it and see whats goen on.