3uz-fe swap in 2003 LS 430 Questions

[AndreasMet]

In a separate thread I asked if a 1uz could be installed in place of a 3 uz.

I have decided to stick with the 3uz based upon feedback here and elsewhere.

I'm planning on buying a motor on ebay (yikes seller has 100% feedback though).

Perhaps you could give some advice on the following questions:
1. Assume I need to do a timing belt change on used motor before installing even if claimed mileage is 40K on new motor?
2. Do I just put new motor in in and connect all electronics and it's good to go? Some people say use old electronics. I'm not sure what that means. If I got it wrong, what stays from he old motor?
3. What can I do with the old motor? I'm going to build a boat, could this be used in marine application?

Thanks. This project is a little over my head, but step by step it's worked out so far.

 

[George_R]

The advice is try to buy an engine from the same body
Loom is not interchangeable between LS430/GS430/SC430
pre-2004 and post-2004 are different too

in the worst case you just swap your harness between your old and new engines