I have a 2005 SLE Bonneville, 3800 series 2 non supercharged and I would want to change over to a Supercharged engine? I know there is a lot of top end things, but if i found a series 2 supercharged, could i take everything on top of the LIM and put it on my current engine? what years would make a good donor ? would i have to change out the PCM? and how would that affect the transmission and such in the PCM if i do? whats your thoughts? suggestions besides buy a */C Bonneville.

Im not an expert but I know its pretty involved. It would definitely be a little a bit of work. There is a lot of info about swapping if you search for it. As for the transmission, the */c engine would be too powerful, you would have to upgrade to the 4T65E-HD transmission.

Kyle is correct. The L67 is too strong for the stock transmission.

There is more to it than "top swapping". Yes, all the parts will swap over onto an L36, but your actually going to produce more power than a standard issue L67 because of the higher compression ratio. You would also need to tune the PCM after the top swap because the current PCM settings are too aggressive for the setup.

It would be easier to just swap out the whole engine/trans/pcm etc. Just like I did last year. Except I kept the original PCM and re-tuned it myself.