I have a 08 needs a transmission will a 05 4l60e work to replace mine that in it now 5.3 v8 ltz crew cab is what I have and the 05 is unknown

 

No, the 05 4L60E does not have an Input Speed Sensor (ISS) and your '08 Transmission Control Module (TCM) absolutely requires it.

According to this document even 2006 was a transition year with some '06 having ISS but perhaps not all.
https://www.transtar1.com/TranstarIn...T-P774-001.pdf

 

ok so then if my speed sensor was to go bad then my transmission would not switch gears would be like in park and neutral correct

 

More than likely you'll only have 3rd gear and reverse.

 

Yes that's that's I had then only 1st now won't move