Well, I swapped gas to diesel in my M-715, but that is out of smog. Look at the BAR website and see what they have to say.
As far as I know it should be legal provide you follow BAR's rules. Which means you have to use an 82 or newer engine and install all required emissions equipment related to the donor motor.
I'd be interested to know myself, so I may start doing some research. I kind of have a plan in the back of my head for a diesel powered "MJ-715". Essentially a Comanche treated to the same body mods the factory used to make the M-715 out of a Gladiator, built on a tube frame , with a good European 4 or 5 cyl TD.
It would be way to cool to tow that behind my M-715 tow rig.
If I remember correctly it is totaly legal to do. As stated above you have to have an 82 or newer engine with all emmisions equipment on it. I believe the other caveat is that you can only use a "light" duty diesel engine; ie from a light duty truck. No cat diesels or large semi truck engines etc... Of course I don't know how you could fit one of those into a cj anyhow.
After the swap you need to take it down to the smog ref and have him verify that it is a legit swap with all the emmisions stuff. He then signs off and supposedly you no longer have a bi-annual smog check.
Anyhow that is what I recall from my class two years ago. I probably have that in writing somewhere if your really serious. Also get to know your smog ref in your area. I know ours here is a real nice guy and part of his job is to help people like us do what we want to legaly. It never hurts to ask.
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