Hola John
Every now and then we get a question that has a unknown for a starting point.
If John had said for his 68, I would have said..." Try the Autolite's # 86".
( The reason for # 86 instead of the # 85's is the engine will burn off
better if the miles are a little high.
Rodger & Gabby
63 Le Baron w/86's
66 Le Baron w/86's