I ran the ladder bars, and on sharp turns like in parking lots, while parking, you could see the rear tire jump as you would turn. Plus the turning radius stunk! Everything was a 3 point turn at least. I know some people don't have issues with it, but to me it wasn't worth it.
Haisleys and enterprise engine both have the mini spools.
You might try
www.puredieselpower.com as he is a dealer for haisley.