AMC Hornet. Rear 17 or 18x9?

[Nothingface5384]

The lil old 14s need replacement
I've already test fitted 245/45-17x8 4.5bs on the fronts

Not sure what tire and rim size to go on the back.

Looking at US Mags Bandits
Both 17x9 and 18x9 have 5.25 BS with +8offset

Tire sizes would be either
275/40-18 or 275/40-17



Now I test fitted some 255/60-15 on 15x8 4.5bs
Reason was they have the same thread width and section width as the 17 and 18 combo.. But they're taller at 27.1 vs 26.6/and 25.7 ..

They have plenty of room between rim and leaf spring..1in.

They physically clean quarter lip but with worn suspension it'll compress and hit lower section right above the rusty section of the lip where its bulged out...
Over 1/2 inch but less then 5/8in


Here's a pic of said 15 wheel which makes me believe both the 17 and the 18 would clear since they're both smaller in diameter