Factory 17" is horrible for caliber clearance!
Made a modified StopTech template for the 300mm Whosh BBK and the Ford factory rim spoke requires at least 22mm to clear. Physically test fitted 16" Dekagram with 5mm H&R spacer (3mm minimum if you custom-fab spacer).
When I had the Whoosh 300mm BBK on the car, I used 5mm H&R spacers with 17" 15-52 Podium Super-touring wheels and used 10mm H&R spacers with 17" TD 1.2 wheels.