The last model of the toploader ( I think it was the last model) had only the wide top bolt pattern. I have been told that the closer bolt pattern can be drilled into the case because all they did was remove the two inner holes of the four hole top pattern.

You may have to turn down the front bearing retainer. The very early toploaders (1964) had a smaller diameter retainer - in 65 they went to the larger diameter. It is not that much larger and the larger one can be turned down very easily to the smaller diameter. I had to do it when I put a toploader behind my 312.