Can a 2013 Buick LaCrosse engine 3.6 L v6 swap into a 2004 Grand Prix gtp
You can swap ANYthing into ANY car if you have enough time and money, so yes it will swap. But not easily.
Since the Grand Prix was sold with a supercharged 3800 V6, why would you take the hard road of trying to insert a 3.6? Find an SC 3800 engine and transmission complete and it should go in much easier with factory parts and have a ton of power.
I have the trans with the engine and it has more hp than the gtp and I have the computer with it the thing is can the engine fit with out any mods
No. Your mounts will be different, your cooling and heater hoses will be different and you’ll require extensive mods to the wiring harnesses. Sure it can be done but it’s certainly not a driveway weekend warrior project.
So why didn’t you put those facts in the original post?
Grab a tape measure and see if it all fits. As I posted, I think it will but since you have the parts, measure and trial fit. As @asemaster master posts, the mounts will need to be fabricated and the wiring will be a chore. You’ll need both sets of wiring diagrams so you can connect those wires the engine computer needs with those wires on the car. You likely will have issues with the engine programming that will need to be sorted out by a professional ECU tuner to turn off the stuff you don’t have in the 2004. There may be some communication between other systems and the engine that will no longer know how to “talk” with one another that will need to be worked out.
Are you getting a hint as to the amount of work this is?