I have a 05 cadillac cts with the 3.6l engine that recently decided to give up on me. I happen to have a gen 3 ls1 t56 combo from a 04 gto that I would like to swap into the cts. Can anyone please help me with this project? I realize it is impractical as **** (because of the cts v) and no easy task to complete but plain and simple... i can't afford a v. Someone please help me out I'm asking for help not criticism. Thanks!

 

I haven't done this swap.
The place I would begin, is to compare the engine stands & mounts for the 8 cyl motor that came on the Caddy (5.7L/346), with that of the GTO. If it would bolt right in, you would next need to know whether the rear of the GTO block would clear the firewall, & that the oil pan would clear the steering & the frame on the Caddy. If the GTO oil pan doesn't clear, there are oil pan alternatives on the market.
Then, does the top of the tranny clear the trans tunnel. Then, where will the shifter come through the floor.
Companies manufacture engine adapter plates, that allow forward/back leeway in the way the entire drivetrain (engine/tranny) is mounted.
A Yahoo search for "Cadillac CTV engines 2005", shows a photo of a 5.7L sitting in the engine bay. As far as the engine is concerned, this could be a simple matter of buying the stands & mounts, then swapping your engine.
Best of Luck

 

This question didn't occur to me, at first...is the stock engine transverse/sideways?

 

It's the correct orientation, just a ton of work. I haven't done it either but I do have an '09 CTS with the 3.6L and I'm pretty sure just about everything under the skin is different...

 

thanks that actually clears up a lot! My main concern now is integrating the ls1 harness into the cts. I have looked at schematics for both vehicles but I don't have a experienced understanding of ecm systems. Any thoughts on it?

 

You'll need to study and identify the how, where and why of each function. This could take a while, as you figure out which wires will be kept, where they will be spliced, etc. Then, there's always some troubleshooting.
Not to discourage you, but as Russ said, it will be a lot of work.
Take it one at a time. If I can do it, anyone can.

 

That sounds optimistic! I'll get to it. Thanks for your insight!

 

You'll probably get better answers in the conversions section.

I'll say it's best to find an 04~07 car in a junk yard so you can grab the wiring harness, PCM, mounts, exhaust....

 

Find a CTS-V in a junkyard and get the harness and oil pan, possibly the transmission.