Stop in for a cup of coffee

dukeboy_318 said
According to my tape measure, the bolt pattern is a 4& 1/4 by 5 & 5/8, but the bores aren’t quite equal.

Well this may not be as hard as it seems.
The inside pattern is the only rare one.
Drop it on the intake and put some studs or bolts in to be sure.

Then check the carbs you have.