I currently run a 18x9.5 +38 wheel as opposed the the +40^ that most guys run.

The Neova AD07s fit without an issue in 265/35. This is after using a fender roller to get a very tight crimp on the rear fenders.
I've got someone willing to sell me some 275/35 Dunlop Z1 Star Specs, but I'm wary of rubbing issues.

Just to let you know how close it is; i got smacked by a DD around mardi gras in the rear drivers side fender; and though the body shop made the repair look almost flawless, the that AD07 did rub untill I had them pull the fender out a few more mms.

Anyone here have experience with both tires and their shape/constuction?

I remember there being some conjecture on here about RT-615s in 275/35 being thinner than AD07s in 265/35 wondering if the Star Specs might be similar.

 

PS section width is .6'' greater on the 275 Star Spec and the overall diameter is .3'' taller

My rubbing issue prior to rolling the fender occurred right where the sidewall meets the rubber thread and no where else.

 

I know you can fit a 285/30 on an 18x9.5 +45 with rolled fenders, but I have no idea what would fit on a +38. I can tell you that an Evo on Dunlops just won the San Diego National Tour, El Toro Pro Solo, and California Divisional Series in STU. You could always buy them and check, and if they don't fit, sell them to me at a discount.