B5100E 4.00-9 tires. Non-existant?

[Big N]

Hey guys, new guy here. I just bought this B5100 which needs a bit of work to get going. I'm currently rebuilding the b445 mower deck and the front pto setup but I'm also really needing to put some front tires on it as well. The dry rotted tires that are on it are 4.00-9 which I haven't really been able to locate locally. I can find 4.00-8 all day long at the Tractor Supply which I can get as just the tire or the tire and wheel combo which is also a four bolt pattern but I haven't had a chance to measure but I'm betting its not the same.
My question is has anybody found this tire size readily available anywhere for a decent price or should I try to modify these trailer wheels I found with the more common size to fit my tractor? Or does anyone have an easier solution for me?
Thanks ahead of time for any input

 

[dmanlyr]

Check Ebay, they are available.

Some of the oddball sizes (in todays world, not in the past) are hard to find locally. Thank goodness for the net though!

A <1 minute goggle search turned up a lot of sources as well.

I hope this helps.

David

 

[Big N]

Thank you sir, I'll check the web a little more maybe I can turn up a set for cheaper than buying and modifying something. Thanks again