Redneckmopar

Looking for some info on a 3.8 swap coming out of a 2000 buick lesabre. Like what all wiring will need to be modified. Also looking for ebcm wiring diagram. Thanks for any info

U.Nanimous

Is that thing supercharged? A quick google search brings up a couple of other forums where someone did a S/C 3800 swap (including a thread on here about one of those other forums), not sure about N/A or specifically from a Buick, you may have to read the others and see how it applies to yours.

If you manage it, don't forget to post some pictures.

Redneckmopar

Thanks for the info I have seen a few forums about them with no real write up on them a few say bolt in engine and engine a blend harness and that's all lol couldn't find anything on here when searching for 3.8 or 3800 venture or u body engine swaps

U.Nanimous

While I do feel the 3.4 is a little underpowered when we take our vacations (really just a weekend visit to family 300 miles away), ours is now basically the wife's grocery hauler so haven't personally given much thought to this swap. I'm just hoping to keep that thing going another 10 years!
I didn't have much time to read any of the links I found so I didn't get much more out of it than you already have, but I saw something that mentioned the GTP subframe bolts right in and the those dogbones fit perfect. It went on to mention trouble with the harness ("blend" like you said), the A/C and I believe something about the throttle cable. Unfortunately while the 3800 is mostly the same between Buick, Pontiac and Chevy, they were mounted just different enough in each vehicle.
And unfortunately there aren't many "Venture" forums around. This is best one I could find and it is SLOW on here. Maybe the best route of attack would be from the other side in a LeSabre forum or one of the 3800 forums like where that S/C Montana is listed.