Toro 4235 rear drive tire alternative

[mrmikey]

As the title says, I'm looking for an alternative for the rear drive tires on my Toro 4235 which have terrible traction. The OE are 18 x 7.5 x 8 lawn tractor tires with minimal traction. I'm looking to put a set of 18 x 9.5 x 8 atv tires on with a bit more grip but the width concerns me.
Right now with the OE tires I've only got 1" clearance to the frame of the mower and the tires measure 7-1/4" wide. Any replacement alternative I've looked at state 9-1/2" wide which would put it in contact with the frame. My thinking is if it's mounted on a narrower rim, which is what I've got, I'll have clearance. Anyone have a set mounted that can measure them for me? These are the two styles I'm looking at. I'm leaning toward the first set. Last set are a bit above what I'm willing to pay.

 

[Alan W.]

Are you measuring the tread width or the section width on your existing tires.
Tread width is usually more narrow than section width which is the widest part of the tire when mounted and inflated.