Disc brake master cyl bore size.

Backspacing on wheels is 3.375

Oh that's miserable. That's a -6 offset.

Well, 215's wouldn't work anyway with that backspacing. They'd stick out further than my 275's. So, I think a 205 is probably the widest you can safely run. A 205/65/15 would be better, a 205/60/15 is only 24.7" tall. That's a pretty short tire up front. A 205/65/15 would be 25.5", which should be short enough to clear and tall enough not to look goofy. Of course, no BFG T/A in that size. They do sell a BFG Advantage T/A, but no raised white letters. Would probably perform better than a regular T/A too. But what doesn't? They make a tire paint that you could paint the side lettering with.

BFGoodrich Advantage T/A