California DMV engine change rules...?

I have a 1971 toyota fj40 with a 350 chevy in it
I had to get it approved by a reff. back in 1980
I had to take it back to the reef. every 2 years until the law changed in about 1985 & it has never required inspection again
I know many others with hot rods older than 1975 that replace engines with no questions ask when they register them