GM guy here, see if theres any differences in the BCM wiring, pinout, communications and so on, as GM generally uses separate computers for the power train and body, but Im not 100% sure on the vue, as they're oddballs. There is very little aftermarket for the "Theta" platform (equinox, torrent, terrain 1st gen, vue, captiva, etc). There might be some suspension stuff for the vue, but I havent looked into it. If youre looking for self restraint on not modding a daily, the equinox is a great choice lmao. I had an 08 equinox 3.4 and while the body stuff, generally speaking, was great and somewhat easy to work on, I had constant drivetrain related issues. Driveshaft went, transfer case went, wheel bearings went, fuel filler neck rotted out, heater core went, just a lot of BS. I drove it till 300K kms and sold it for $500 to a mechanic buddy and as far as I know, it's still driving to this day.
Keep in mind though, that the powertrain would be great, but everything else is GM junk. Im in the middle of doing a rear wheel bearing on my moms 07 torrent and it is a living hell. That being said, parts would be plentiful.
I saw a guy who swapped his montana SV6 with an LS4 out of an imapala SS. His main issue was the SRS system wouldn't communicate right, since he was running two BCMS. One for the imapala stuff (cluster, ABS, etc), and another one for the montana stuff (HVAC, lighting etc). Who knows you might be lucky and might have to swap just the cradle then the engine and wiring, but I doubt it. The fuel system would probably need to be swapped over and maybe other little things like front hubs etc.
I highly recommend you join
www.terrainforum.net and pose some questions there, Im on it and its a great community and they probably would have more answers for the swap and would know the differences.
