The 1415 gaskets are the correct size for the old Superformance headers that everyone used before (right). They are 1.48 tall and 1.25 wide....the "402" headers used mostly after car #2600 use the "402's" for ALL Roush motors and they are 1.62 tall and 1.42 wide fitting the Roush / AFR head.
The photos show both headers. When you look on the top of the flange near the firewall you should see"402" stamped into it, if not, type in "Superformance Exhaust" in the search thread. The old style small headers choke your exhaust about 30 % or better.
The 402's are on the left and a set of the old SPF headers on the right that have been used on a Roush 427. You can see the overlap. An angioplasty is not going to help in this case....The 1415 gaskets seem to be the same size as the old header shown on the right.
