Front to rear tire width balance

[next69]

I read on the DSE website that the maximum tire sizes for a 69 are 245/45R17 on the front and 275/40R17 on the rear. I seen on Wayne Dues site that Mark Stielow put 275/40R17's on the front of the Mule and 335/35R17's on the rear, obviously Mark obtained these larger sizes by mini tubbing the rear and narrowing the front subframe. My question is I really like the look of the 335's on the rear, but can not afford a new front subframe, if you run the 335's on the rear and 245's on the front will this cause the vehicle grip to be disproportioned, also is there any way to modify the factory subframe to handle a wider tire.