Thats going to be a hard size to come up with . Where are you located . I work for a tire shop in Triangle we might stock the 245 45 17 but that 275 40 we would have to order . and since today is Friday it wouldn't be here till the earliest Monday .

I hate to say this but have you tried NTB they stock some fucked up sizes there .

IF you could hold out till Monday give us a call 703-221-6194 ask for Bill he's the owner and the one that would try and find you the best deal .
Ps don't get offended if it sounds like he's talking down to you on the phone he's a stickler for doing the right thing for the customer so .