Stop in for a cup of coffee

Well the link I posted earlier explained hte front and rear bores were shifted for the larger carbs. But the bolt pattern stayed the same.

So lets figure out what you have and then pick the easiest or fastest. it may not be both. LOL
According to my tape measure, the bolt pattern is a 4& 1/4 by 5 & 5/8, but the bores aren’t quite equal.