Another point of reference for you. On my '68 I'm running BF Goodrich g-Force Super Sport All Season Radial; 225/45R17 mounted on American Racing Wheel Torq Thrust M Anthracite W/Machined Lip. 17" x 7" x 4" Back Space Tire Part # 245WR7GFASXL-26483; Wheel Part #AR105M7761AML. Tire is 25" tall. Front suspension is basically rebuilt stock, lowered by cutting the spring. I'm using an Addco 1 1/8” diameter front sway bar Part No. ACO-599 with KYB Gas Shocks Part No. KG4515. I'm running Wilwood disc brakes which move the hub out 3/8". Everything fits well. It sounds like you need a little more back space in your wheels or shorter tires. According to BF Goodrich, 215 60R are 25.2" tall, 215 65R 26" tall and 215 70R 26.9" tall.
Hope this helps you sort it out.
Nice wheel choice for a FGF, by the way.
1967 FB 400, original CA car (smog), now 455, soon to be out of Paint Jail 2006 Mustang V6 Pony, factory ordered, retirement cruiser and future classic(?) 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI