Never heard of a "spacer" myself... There is a Cobra Racer here in town but it has the 10" wheels.
It's in a shed about 1/4 mile toward town from me.
Like everything RedNeck... He has not run it in 8 years, but refuses to sell it.
The seats rotted out, the aluminum looks like steel wool (salt air), none of the cables move, and the cylinder is seized.
I offered 300, he wanted four. I asked again this spring, and he said he re-thunk it... 450.00. I really wanted to fix it up for someone. It's too small for any adult guy.