LS 1st Gen vs 2nd Gen Engine Differences

I have a 2005 LS, untitled with a bad transmission, AND I have a 2000 LS, titled with a bad engine. I want to keep the titled car, its in much better shape. Both are 3.0L, V6. I wanted to put the good motor from the 2005 into the 2000, but from what I now understand, the engines between the gen1 and gen2 are different.

How so?
Do they use the same transmission at least?
What would need to be exchanged to make the gen2 work in place of the gen1?

Thanks for any help! :confused:

I'm just going off of what I recall reading here, not any real experience trying this. I don't think the transmission will be an issue, but you might need to swap the upper intake between the two engines. It seems that things changed with the intake and maybe some added sensors.

Hey, you said "any help". ;)

-Rod