From what I understand you options are:
- Acquire a full 2007/2006 Monte (maybe even Impala) with a LS4 v8. You will want the entire car because you will need a lot of misc pieces to make the swap.
- Do a lot of custom fabrication to get a v8 in there. You are probably limited at options in the FWD world.
- Do custom work to convert the body to RWD and put in a v8 drivetrain.

- Get a 2006/2007 Monte SS that came with a LS4 v8.


those are pretty much the most common, possibly only options.

 

 

Sounded like you really wanted to switch to a v8


You can certain do something with a turbo or supercharger. There are plenty of threads on this topic:
- You can top swap the 3800 you have with the top end of a L67 (3800 SuperCharged). PCM tuning is required. Because of the compression difference from you L36 (no-SC engine) and the L67 (SC engine), it's not a simple "swap the PCM" item.

- You could completely swap the engine out for an L67.
- You can Turbo Charge the car. I believe ZZPerformance sells a budget turbo kits.


I honestly don't know the ins and outs of these three options, but plenty of people have done them and there is lots of information on here on MCF.com and many other sites about boosting that exact engine.

 

I have had talks with an ASE master certified tech that said actually changing over the 3800 to the 5.3 in the 06 generation would actually be easy except for stuff like fuel and the wiring. But a easy engine swap would be just to get the 3800 SC out of the same generation and stick that engine in.