would these headers fit?

Sounds like you have a set of car headers on it now.
The headers I had on my Ramcharger with a 4-speed you could change a full size starter without taking the headers loose. I bought them new years ago, but dont remember the the brand, but the where cheap, like Blackjacks or Headmans.

Did you have to put a small ding in one tube to clear the mini starter, this would confirm car headers.
I have an engine start stand that uses a truck 143 tooth flywheel and bellhousing, mini starter and car headers the car headers are real tight on the mini starter.