WILL THIS WORK?

[cudabuyer]

I am researching wheel & tire size for my 70 Dodge Challenger Convertible - have recently installed Moser 60 rear - 1 inch shorter rear each side (B Body rear end) 

Replaced leaf springs with Ridetech AirBar Multilink suspension Air bags

Currently have 235 60 15 front       255 60 15 rear

Clearance in rear wheel opening is 13 inches

Would like to order 18 X 9.5 wheel and 255 40 18 tires for rear or 275 45 18

Should have an inch clearance on both sides of wheel in rear with these wheels & tires.

THANX

[hotrod98]

The 255 40 18 tread is only 8.2" wide. Wouldn't be right for a 9.5 wheel. The 275 40 18 tread is 9.4" wide and is .8" taller. Just measure that backspace carefully. I think 4 1/4 would be just about right with the narrowed rear-end.
Normal back space for an 8" wheel is 4 1/2, 9" would be 5, 9.5 " would be 5 1/4, deduct an inch for the 1" narrower rear end. Measure your car to see if this will work.
I went the safe route on my chal convert with 255 40 17" on Boyd Smoothies on back. Just for grins, I mounted them on my 71 cuda for a show this weekend. They look good, but I think that I would have liked the 18's even better. I do like the taller sidewall though. They don't look as ricey that way.

[cudabuyer]

I am looking at Newstalgia Wheel - Billet Specialties - "Fast Lane" Let me know what you think.

[70rtshaker]

Install the narrowed rearend, you probably do not need to relocate the spring pearches and use a 3/4 offset shackles and offset front hangers, you could make this happen using 9,5 wide rim with a 4,5 inch backspace.