Aurora, 2001, swap 3.5l for 4.0?

[mvkeith]

Can you swap the 3.5l for a 4.0L? Are the trans different? I know this year offered both the 3.5L and the 4.0L.

Appreciate any input.


MK

[Autobanaurora]

Yes, you must take the ECM. Why not just go with the Cadillac 4.6? Take the wiring harness and ECM, your good to go...

[phewop118]

It may not be quite that easy. The 3.5 used a medium duty transmission from the W-body platform, while the 4.0 used the more hefty unit common to the G body.

[Jrs3800]

The 3.5 Twin Cam, 3800 NA and 3800 SC units used the 4T65-E Trans where the 4.0 and 4.6 Caddy V8 engines used the larger 4T80-E Trans...

Just to note it, the W Body LS4 5.3 V8 is attached to a slightly beefed up 4T65-E..

[Sharp84]

Bump, I want to do this.

I have a 3.5L has 4t65e but tranny is gone. 330k km

4.0L is 95-99 Engine (1st gen) with 4t80e. (Can get it for cheap) 150k km
Wondering if its possible to swap it? I know I will need ECM, and maybe wiring harness and motor mounts?

Thanks.

[Jrs3800]

Yes this can be done.. You will need all of the parts, Axles, Mounts... All of the related parts and accessories, PCM and wiring harness... And some really good schematics.. It will be a lot of work..