You can run whatever idea you come up with based on what you find by the referee https://asktheref.org/
I am pretty sure if you call they will tell you what they will accept. I think a rebuild of the OE motor might be all they will accept since they are trying to get old cars off the road. But the Ref might allow a newer cleaner motor if it is stock CA emissions.
And then I have had this link saved because I might win the lottery some day.
http://www.precisionengine.com/rebui....html#question