DTS L67 swap?

Okay, I understand what you're saying. I'm not sure if you're familiar with these generations of cars from 2000-2005. But for starters. Again, I refuse to swap subframes because the Bonneville Trans is a weaker transmission compared to the 4t80e. And the Bonneville has 240,000 on the body, also the body is severely rusted. Which is why it is now a donor car only the engine can be saved. As far as the Cadillac, here's what I compiled from a forum as this is for to swap a Supercharged Series 2 V6 from a 2000 Bonneville SSEI into a 2005 Cadillac DTS Premium, if there's anything I'm missing please let me know.

*1) SSEI Engine and Engine Wiring with minimal modifications to the DTS hood fuse box connector. All of the Caddy interior electronics will work properly for the 3800 s/c v6.

*2) SSEI Exhaust downpipe can be bolted directly to the DTS exhaust. It will retain the factory 3800 starter location. Also, the A/C lines route the same, so the DTS Condenser wouldn't need replacement. The DTS Mounts is Similar to the Bonneville, so either mounts can work. The DTS accumulator is also in the same place. 2000-2003 Bonneville SSEI models came equipped with Stabilitrak 2.0. So the ABS wiring is also the same as the DTS.

*3) The DTS 4t80e transmission can be used with the 3800 s/c, just re-drill the flex plate for the four bolt converter and re-drill one bell housing bolt.

*4) 90% of the 2000-2005 Deville DTS wiring was much closely matched to the 2000-2003 Bonneville SSEI. All the major SSEI wiring plugs do match up to the DTS, so reprogram the BONNEVILLE ECM to match your specific DTS VIN. But REUSE THE BONNEVILLE ENGINE HARNESS. Bypass the communication line at the electronic suspension module, so there's no "service suspension". You'll also have to do the "RELEARN" for the Bonneville ECM once everything gets converted over to the DTS. Key on till the security light goes out on the dash (approx 10 minutes) cycle key off, back on twice more (30 min total time) to get the DTS can recognize it.