Capturing a piece of early 70s Trans Am mojo...what can be done?

All 4 manufactures were in Trans Am in 1970. And many of their sub brands too: Chevy, Ford, Pontiac, Dodge, Plymouth, AMC.

But in 1971, they all bailed except AMC.

The economy in 1971 took a downturn and racing budgets were being cut. I'm sure SCCA has some blame too as they weren't really experienced with this level of manufacture involvement.