I have converted a V-8 distributor housing to work on an inline 6, but it's a very complicated procedure that I wouldn't reccomend unless you're a master machinist. It involves fabricating bushings and cutting the housing to the proper length, and changing the reluctor and pickup assembly out for a 6-cylinder unit, etc. It's also necessary to machine the original locating shoulder off, and fabricating a mounting bracket to position the housing at the right height. Then you need to make a new shaft, and braze a mechanical advance assembly on at the right location. I've been at the auto repair trade for 50+ years, including a lot of round track racing, and adapting a V-8 distributor to a six is a challenge for me.
Jerry