I did this mod to my Blue Boy and it worked great. I got the back tires from Harbor Freight. (they are the cheapest)
The fronts came from an online company Access Casters (PN-4560-CC). , measure your front tires and do a search online for that size tire and you should be able to find them at that website Access Casters.
Now to do the mod to the front tires you do have to replace the axle with some longer drill rod which you can get from Home Depot. Use the same diameter, I think it is 5/8"as the original and just cut it to legth with a hacksaw. Then either drill a hole in each side and put a cotter pin in it or use them pressure fit caps, like what is already on the axles originally. You will want some washers too to ofset the tires from the blueboy.
I did the same for the rear axle drilled a hole and used a cotter pin and washers too.but you dont have to change the axle you can use the same rear axle with the tires from Harbor Freight. Also on the back axle there are plastic bushings they use to set the tires off the blueboy. I just sanded them donw on a disk sander until the 10" tires from HF fit on the axle with enough room to drill a hole and put the washer and cotter pin in it.Edited by: fixit5561