RE: 1/4 Dune Buggy in the works
Wow, impressive!
You might need something like a panhard rod, holding the axle in it's side-to-side movement.
Remember, the tensioner should be on the unloaded, or lower side of the chain loop, so when you accelerate and the upper chain section pulls straight, the tensioner isn't affected.
Do you think you'll be able to incorporate some mini-bike coil shocks from the Northern catalog?
Glad you got the pic size worked out.