LFX engine swap

JLF_1977 · Apr 22, 2025

So, I've kicked around the idea of turbocharging my 3.9 Lucerne because turbo V6 Buicks ARE a thing. I know that will be a pretty involved process, and while it could be fun, I'm not sure I'll get what I REALLY want from the car. I priced up a 3.6 LFX and transmission complete with harnesses and control modules. Has anybody considered doing this swap? You get 300+ HP, better tunability, a six speed automatic, and a better engine. Those parts can be had for under $2,500.

2007LucerneCXL · Apr 23, 2025

Any swap is possible. The Lucerne swap is asked about often and to best of my knowledge has never been done. This doesn't mean a lot of people claiming that they have done it but no photos or documents just a post on the misinformation highway LOL.

Issues are programming the engine and transmission, pick any combination, to the Lucerne OS and fitment with existing components.

Adding more power to the V6 may be easier but the 4T65E transmission is a glass house and a complete review of all mechanical equipment is required.

JLF_1977 · Apr 23, 2025

2007LucerneCXL said:
Any swap is possible. The Lucerne swap is asked about often and to best of my knowledge has never been done. This doesn't mean a lot of people claiming that they have done it but no photos or documents just a post on the misinformation highway LOL.

Issues are programming the engine and transmission, pick any combination, to the Lucerne OS and fitment with existing components.

Adding more power to the V6 may be easier but the 4T65E transmission is a glass house and a complete review of all mechanical equipment is required.

The 4T65-E isn't my primary concern if I beef up the 3.9. We can make them nearly bulletproof. It's the differential and chains that are the primary issue. In a different project, I ran 520ft lb torque through a factory unit. The one in this car has a shift kit, increased line pressure, and shorter commanded shift times. It's pretty impressive how quick the thing will shift. I also run an external cooler, and change the fluid and filter every 10,000 miles. I know the 6A transmissions are good units, though I don't know the torque capacity on them.