Tyre/ Rim Question

I have a 2006 NP Pajero - standard tyres are 265/65 R17 on 7.5" rims. Need new tyres and am contemplating getting Bridgestone D694 LT's in a 275/65 R17 - this will give me a diameter 14mm greater than standard but most importantly increases load capacity from a 116 to a 118 rating. Have been told that fitting the 275/65 R17 to a 7.5" rim will result in the tyres wearing out very quickly due to 'bowing' of the tyre.
Has anyone any knowledge/ experience of this?
Thanks and cheers

TG

PS - any comments re the choice of tyres??? - will be doing a lot of touring towing approx 1300kg Adventure camper - intend to do a fair bit of offroad but not hardcore - a lot of bitumen driving as well getting from A to B!!