What are the issues running different radius tires front and back? Does it affect the handling, ABS, or other? Willing to cope with not rotating tires and only spare for front. For me its an appearence thing with larger radius tires say 16 in rear with original 14 in front.

 

You're talking about running rears with larger diameter than the fronts. It is often done for handling reasons but the difference is slight, perhaps a quarter-inch. However, you appear to be seeking a large difference, say 2". Why? What appearance is going to be improved? Is the droop nose in vogue now?
Just what are you trying to accomplish?

The issues you could involve are different roll centers between front and rear which try to lift your inside front wheel in corners and related suspension misalignments which leaves handling a bit edgy. Needless to say, too, it may look a little funny, not unlike a stunted golf cart.