will transmission from a 3.4L LS fit a 3.8L SS ?

yes it will.

yes it will work

Will a 3.8 fit in 2005 montecarlo 3.4

Will a transmission from a 3.4L fit a 3.8L Ls

The transmissions from the 3.4 and 3.8 is the same

And engines will fit with some work but if you put a 3.8 supercharged (L67) in the Monte and a heavy duty transmission it'll be the same transmission labeling except it says HD after you will have a 9 second car on the quarter mile

will a ecm from a 03 monte carlo with a3,4 fit a 01 monte carlo with a 3.4

I installed a transmission in my 01 monte carlo ls with a 3.4 I have a code 1810for the transmission I test ride the car and it shift through all the gears but when I shut the car off and start the car back up and drive it the car only shift from first to second Do I need to have the ecm reprogramed by the dealer