GTS Vs. Swinger
I would limit it to 340 or 383 only and would say a 340 GTS convertible, if not a convertible and hard top only, I would take the Swinger 340 4speed, I have owned both hard top 340's, but the GTS was 68 with an auto. The R4, that someone painted orange, 69 Swinger 340 4speed 3.91 rear I had was lots of fun!