D300 Wheels

[Deeter]

I have a 68 D300 dump truck project and was hoping to ditch the original split rims for something less murderous, and ditch the tubes while we're at it! The problem is that no wheel manufacturer in the world makes a 6x7.25 bolt pattern wheel. None. Anywhere. Has anyone come across anything that might work? I've searched for adapters too. There is a custom shop that could make them for me, but I'll be dropping $5.5k for wheels on a truck I bought for $600. Any help would be appreciated.

[PwrWgnDrvr]

The GM 10 x 7.25 wheel can be modified to fit. 2 holes line up and the other 4 can be bored.
Been there, done that, with an electric hand drill and 90 degree countersink - 35 yrs ago and 200,000 miles w/o issue - (20" dually wheels on a W300)