Are 4L60E year specific?
 

I have an '06 LQ4 that I'm trying to find a 4x2 transmission for. My understanding is that any 99-06 transmission will bolt right up with no issues. Is that right? Motor originally had a 4L80E 4x4 bolted to it.

Are the internals the same on the trannies that were used on the 4.8 and 5.3 motors?

The wiring is different between the 4L60E and 4L80E. If you have the "short crank" engine they are a bolt in swap as long as you have a transmission from a Gen III / IV engine. If you get a V6 variant the input area is different and is setup for the depth of the old Gen I / II small block and will require a spacer on the crank snout.

Happy hunting.

Thanks for the clarification.

Even better thought would be to find a 4l65e from a 4x2 truck(03+) then you dont have to worry about fitment issues, and its built stronger than the 60e.

What's the difference between the two? And it shouldn't matter if it sat behind a 4.8, 5.3 or 6.0 should it? Internals should be the same shouldn't they?

The 65e is built with better internals than the 60e. Some guys are rebuilding the 60e with 65e internals for better strength.