As I referred to in another thread, I will be replacing the engine in my 1999 Denali this summer. In 2001, the Denali engine was upgraded to a 6.0L with more 25% more horsepower than the 5.7L. So my question is how hard would it be to replace the 5.7L with the 6.0? I don’t think space is an issue and putting in new mounts is not that big of a deal. I’m thinking more of any electronics issue (note: I will be replacing the BCM at the same time) or hooking it up to the tranny. Speaking of that, if there is an issue with connecting the 6.0 and the tranny, should I consider maybe replacing the 17 year old transmission with one that will connect up to the 6.0L?
Your 5.7 sounds like it’s an L31, which is a Gen II small-block (LT1 family.) The 6.0 was a Gen III. You might be in for a lot of work crossing generations like that.
It is a L31 5.7L. Also the transmission the 6.0L tied into is the 4L60-E HD
Possible the biggest issue is getting all the emission stuff to work. If you live in an area that still has emission tests, you probably want to forgetaboutit.
Forget it if you live in California.
Almost certainly not an issue to go with the 6.0.
I would find a Denali/Escalade/Silverado message board and do a search on engine swaps. You’d be surprised what can throw a wrench into your plans when doing a swap, it’s best to learn from others’ experiences. Would bet 100 internet dollars that someone has done this exact swap and posted about their experiences.