/6 camshafts
Call Dave Crower at Crower Cams. The phone number is at the top of the link below.
https://www.crower.com/
He made a custom grind for my ex's 64 Dart with single exhaust and one barrel carb that had 260° durtion and .495" lift. She's very happy with it.
They don't list slant 6 cams on their site because they are low volume, but he's happy to make a custom grind for your application and does a good job.