Thats odd...Dinball is usually reliable for some hard to find parts.

I purchase form Amainhobbies, they are quick, easy to use, and ship fast. They also have some nice discount codes on some items.

Back on topic, I have a Hot Mod PLus 21-5 in a MBX-5 and it hauls ass. Most people use them in a truggy, and in a buggy, it has insane bottom end nut. I ran at the track yesterday and beat every buggy/truggy out of turns in practice...its insane .