Some higher stall converters may whine but most likely converter bearing going. Trans pressure gauge might take the uncertainty out of transmission having issues
Try going maf less. Ported turbo. Some have had luck with a tornado. You have an air restriction when letting off pedal. Upgraded intercooler probably adding to your problems. Better heads.cam would help.This surge will shorten turbo life. Destroy maf.turbo seals or turbo. Gradually lifting gas...
Believe check valve is behind coil pack. Is there constant vac on purple line at controller. Disconnect it and check. Then pull other lines at controller and check for vac. Also check canister at left frt wheel well area.
An ac-14131 is a art carr converter. Not sure what your p/n actually is.Hard to tell lock vs non. Usually furthest splines in that turn with resistance is a lock up.