1. get fr tires unmounted. $5 apiece
2. drill holes on other side of the rim $0
3. mount new stems. $6
4. reverse old stems and glue them in. use 3M pliobond. $2-4
5. remount fr tires. $5 apiece

total cost, $30.
the look on your pal's face after he paid for spacers and new lugbolts (not to mention the struggle to put new bolts in the hubs). priceless

not rocket science. no spacers. no strain on lugbolts.

 

If you want to fix the valve stem problem, go to your local John Deere dealer and tell them that you want planter stems. They are almost flush mount. Our dealer keeps several sets in stock here. Says that he has never sold a set to any farmer. Just punks with wheelers.

 

man, can't get any easier than that!
i was gonna go the dismount/remount route and put new tires on but i'm still gonna check out those stems.