70 dart swinger slant turbo build and mild restoration

So I'm laying out the design for my header kinda eyeballing it right now and there's about and 1/8th inch difference between the offy intake and my header flange should I have the intake milled down so there the same or are there tabs I can buy that will make up the difference between the 2 or go to a 1/2 header flange remember I wanna go into production with the headers so milling the intake is kinda out because I want the customer to have this as easy as possible because anyone who's built one of these knows they are overwhelming at 1st