According to carfax, my 93 SD is registered in SoCal, salvage title and all.

All you need from the donor is the short block and IP. Everything else will be on the 3.5 and likely in good shape, including - head, manifolds, turbo (might as well use the 55 trim), oil pan, oil filter housing, etc. You can even keep the donor long block intact if you're confident in the head. Then you can offset costs by selling the 3.5 head. There's some demand for the 3.5 cranks as well. I heard it's the key to stroking an M104 to 3.6 liters. It's all nuts and bolts, no fabricating.

What you should pay for the S350 depends on the condition of everything else like transmission, ACC, interior, amenity features, etc. Being a 95, it's subject to disintegrating engine wiring harness but even a catastrophic wiring harness failure shouldn't strand you. www.v12uberalles.com is a good resource to keep 140 doodads humming.

I don't think the swap will affect residual value in a big way. Anyone who knows will be happy to have a 3.0 block. Throw in the 3.5 block for those who care. Note that decent gasser 140s can be had for less than $4000 and some for less than $3000. That'll probably have more effect on the future value of an S350 than engine displacement.

If time and labor mean nothing to you, throw in a head gasket and see how much that cuts down exhaust smoke. Lucas oil additive did a fair job reducing smoke on my 93 SD while I was waiting for Hit Man's block to arrive.

Sixto
87 300D