What's the secret for changing the project tempo without it shifting the existing tracks? 
I imported and then recorded a bunch of 75 bpm into a project set at 80  
They go out of sync with each other if i just change the project tempo.
I tried selecting them all first but some are good and some aren't.

Set your Now time at bar = current tempo +1 (81 in your case), hit Shift-M (Set Measure/Beat at Now), and enter target tempo +1 (76 in your case) as the measure. This will change the project tempo without altering the absolute start time or duration of any audio or MIDI already in the project. You have to add the 1 because there's no bar "zero".

Thanks.
Set the now at 81
Shift M did nothing but I found Project/Tempo change.

Tempo pop up has a box that says 80.
I changed to 76
Still adjusts tracks out of sync.

That got me thinking.
The odd timing was on clips that started further along the time line.
I noticed only the track clips that started together, played together.
I slip edited ALL the track clips to start at 2
I placed the Now Time at 2 (the start of the first of my tracks)
Project/Tempo change
I checked the "Insert a new Tempo" and typed in 75
Perfect.
Thanks for getting me going.