Whenever i list a custom front end on eBay despite giving all the relevant measurements some pedantic git always asks "but how much over are they ?" so here are the official baseline measurements for standard forks, measurements are taken from the bottom of the steering stem to the centre of the wheel spindle. Info is from AEE Choppers mid '70s, so dont argue.
While i am at it these are dimensions for a Wassell P'nut but drawing possibly isnt to scale! I cant remember where i got this so you can argue if you must.