not sure what this is...

[MarauderMatt200]

when im driving on the freeway 60MPH or faster, when i let off the gas then tap the throttle theres a small clunk. I thought it could be U-Joints but a mechanic looked at them and said they are fine. I dont know what else this could be. When im cruising through the city at around 40MPH i try to recreate it and it does nothing. just a smooth transition. The rear end was rebuilt added 4.10 gears and new axles by a reputable mechanic. Any idea where and why there is this clunk feel?

[fastblackmerc]

Combination of all the play in the drive train. Didn't your mechanic tell you that?

[88CuttyClassic]

Converter lock/unlock is my guess. I couldnt stand the feeling on my gbodys and installed a on off switch to controll it. Not sure if that's an option on fords.

[MarauderMatt200]

Combination of all the play in the drive train. Didn't your mechanic tell you that?

so is this normal or should i get it looked at more in depth?