Have looked at some previous posts and for my 409 I think I have narrowed it down as follows:
Tires on the car are 600 X 16 or   5" ( footprint) X 28".
A 185 VR16 would be close...need to check footprint and I am considering these 2 options:
https://www.cokertire.com/185r16-michelin.html  Michelin X  at  $300
or 
http://www.lucasclassictires.com/185...-CA67-518p.htm  Pirelli Cinturato  at $400.
Thoughts??
Anne