Okay, after hours of searching multiple sites. I thought I would pop the question because of a lot of mixed debate I have read. I live in California(what a lovely state to do this swap in) and I would like to plan on buying a late 80's or early 90's Chevy suburban 2500 and I would like to swap a 94-97 second gen 12 valve with a nv4500. Now I know the swap would be pretty straight forward and I am not concerned about that part of the swap. Now what I'm wondering is if I retained all stock components and air cleaner and all that emissions B.S. from the downer truck and put it into the suburban and took it to a Bar reff. Should it pass and then become pre smog diesel to add modifications too? It would be a truck older than the engine (and the truck would become pre 97), it would retain all emission controls. Would I get caught up and told that its not legal or would it be a peace of cake and go on by then I could go to DMV and get the title changed? I'm asking this right now before I even proceed buying a suburban to see if its possible. Id just like this cleared up because I personally cannot find anything on the internet without it all being a grey area. Thanks I appreciate anyone's input.

 

I think the trick is to start with a diesel Suburban, ensure the cummins is a newer model year. But I'm not in cali, so I dunno for sure.