Hello! I am the owner of the Adequate Willys Aero-Lark!
I built it with a couple of my racing friends. I bought it non-running from some guy on Craigslist after searching for a few months for a reasonably-obscure American-made car.
We raced it with the OE drivetrain (just changed the fluids!). It's 3 on the tree, no OD. Tires are horrible high treadwear rating so that we slide instead of hurting the delicate suspension.
The things we had to do to make it race ready were: make the engine go (all the wiring was rotted, but we kept it 6V), completely re-fab the brake system (but kept it drums all around), put in a fuel cell (the OE fuel line was rotted out), and cage it.
We also put on new shocks (rears are common; fronts are for a '71 Challenger with the dust shields cut off!), installed auxiliary brake lights on the parcel shelf and wired in a tach and oil pressure gauge.
The theme, if you don't get the joke, is a spin on the "Fabulous Hudson Hornet".
By the end of the race, the gaskets were all leaking dramatically and we had to come in after 20 minutes on track to add a couple quarts of oil. But the engine held up and, after stripping it down post-race, it looks really, really good.
We managed to take the top prize in Lemons: the Index of Effluency.
I'm happy to answer any questions about it. We are very proud of it!