Nothing gives a better musclecar look then the 245/60s on those rims IMO. The 25.6" tall almost perfectly matches the factory original tire height of 25.5" so your speedometer and odometer stay correct. Yes you have to watch tire inflation pressure so that they wear nicely but thats not too tough. If you want a taller tire the 215/70 or 225/70 work but serve to make the already too tall gearing.worse ie making acceleration even slower.
In the muscle car era if it had a small block it was your moms car.
When you turn your car on does she return the favor? Life's short enjoy your ride. Hybrid burns gas & rubber. Check out my photo album.87 Olds 442,
Blue on Metalic Silver with 275/60/15 drag radials on 15x8 442 wheels, 10-1 509ci Cadillac, 800cfm Q-jet, Performer intake, Street ported heads, 230@50 518 lift cam, Headers, Built 200-4R, 2800 stall lock-up converter, Electric fans & in-tank fuel pump, Factory AC, All factory guages work including tach & oil temp with the 509, Functional Hurst hood & rear spoiler, 36mm hollow sway bar, 3.42 posi 8.5, 17.0 mpg hwy, sold 87 Buick Grand National,
Tuxedo Black w Chrome 275/50 drag radials on 15x8 GN wheels, 231 Buick V6, TE-60 turbo, Stretch intercooler, 42.5lb injectors, 3" downpipe, 3000 stall lock-up converter, Meth/water injection, 3.42 posi 8.5, 22 mpg hwy, original owner ~ Goal for both cars 11.8 ETs / 115 mph in the quarter reliably on pump gas