In 1970, Dodge was not planning on a 340-powered R/T Challenger, as up to then, that meant a big-block was standard. Seeing that Plymouth was releasing a 340-powered 'Cuda, it was decided to offer a special package to incorporate the 340 in the Challenger lineup, and the A66 package was created.
This site was created to gather the known information about these special
1970 Challengers, and host the Registry for them.
Most of the discussions on the A66 Challenger is on the dedicated Facebook group ''Challenger A66 Group''
On For E Bodies Only: https://www.forebodiesonly.com/forum/threads/a66-challenger-registry.20327/#post-117548
and on the E-bodies.org forum