Fitting TTi headers on a 273

Mattax, tolerances stack up, could just be a slight shift on the mounts to give the required clearance. Also doesnt even need to be 1/8, I bet 16g would work too, just enough to give it a backing. 16g over a 2-3mm gap will provide plenty of support for a flange. UK's headers collectors are way up there, I think he has much more clearance/leaway than we usually see with full or 3/4 length headers. maybe just a kiss on the outside of the flange with a grinder. plenty of meat there.