Does anyone have experience with changing engines and smog ramifications?

I want to replace my existing 86 diesel Suburban, that is body-rotting away <note, tear running down cheek>.

There is only maybe one up for sale in the US at any time and it is usually in Maine or beat to hell, or something. But there are a lot of very straight gas ones available. But I like diesel! I like 20MPG! I like the 800 mile range when I am wayyyy off road. I like the no fire hazard.

So my question: What happens if I get a gas Sub and diesel it,
get the smog notice and take it in?

I'm in California ...