Hello I have a 2006 Monte Carlo LT with the 3.5 v6.
I love my car but want to do some performance upgrades to give it more power but keep coming to dead ends on info about my engine or mods etc.
I have decided I want to swap a 3.8 v6 into it to have more flexibility with upgrades.

I’m currently trying to understand what all is needed for this swap to happen and don’t know where to start, I am currently struggling and all help is much appreciated!!! Thanks

 

Honestly, not sure anyone did that engine swap. I am going to assume it can be done. My guess would be given the changes GM made in the wiring and PCM for the 06+ Monte, you are going to be best looking for a Series III 3800 (which had drive by wire instead of cable drive throttle body and hopefully a fairly close to plug-n-play PCM and wiring). That being said, your donor car is probably best as a Grand Prix (I think 2004 and newer).

It would be neat to see a 2006-2007 Monte with a 3800, but curious if that will ultimately be worthwhile vs working with a custom shop to do some stuff with your existing engine (like adding a turbo).

 

I don't know anything about compatability between the older and newer modules.

Its certainly possible as there is always the 'nuclear' option swappers in other platforms do - just swap all of the electronics + wiring from the donor car over to the current one. That 100% ensures everything will communicate and work properly. No doubt thats a huge amount of work though, but at least running / driving donor cars are cheap.

A good starting point is probably picking up the wiring diagrams for your current and potential donor car. Thatll give you some clues about potential compatability (ie is one module fed separate signal wires in the donor car, but in the newer one is replaced with a single data wire, etc).

Another option- maybe its easier to just buy a 3800 car and swap the newer front end on? Not sure what parts of your car you're attached to that prevents you from just buying a 3800 6th gen.

 

It's more of having the bcm talk to the ecu that's where it comes down to. You can swap it with the 3.8 the pin side is the bcm talking to the ecu I think there is a variable there that needs to be sorted not sure