old topic wheels

[hifi875]

have 69 camaro, multileaf w/1" lowering blocks, drum rears. hotchkis 2"lower springs w/disc brakes up front. had 17x7 4bs w/21545 up front, 17x8 4.75bs 24545 in rear. absolutely no problems anywhere.
i want to try some coy c5 18x9.5 5.5bs w27535 in rears, and 18x8 4.5bs w/235/40 m in rear. will they fit w/no problems? any other tire recommendations size wise? any help would be appreciated. any knowledge on quality of coy wheels. i am used to american racing tt2. thanks,mike