Running Two Versions Possible

[Duramax 6.6L]

Is it possible to run both 7.5.3 and 8.1.1 at the same time on a lab top if a custom folder s selected during install for 8.1.1.

After the Flash Scan is updated to the BBL, will it still work with 7.5.3

[joecar]

No.

Don't select a custom folder; just install 7.5.4 and 8.1.1 to the default folder.

(8.1.1 is the EFILive Explorer and not the scantool/tunetool.)

You should run 7.5.4 which comes in the BBL update package.