Ok, have a comma.

Or even more clearly, "Boeing 737 NG and 737 Classic", since it wasn't obvious to me that they're all 737 variants.

And why not just "NG and Classic"? Really curious, I see this replacement of "and" for a comma in a lot on headlines, and I don't know why or where it comes from (English is not my first language). Is there a name for this?

Most english speakers also wouldn't be familiar with the term, but it is called 'Headlinese'.

https://en.wikipedia.org/wiki/Headline#Headlinese

Imitating this style is a good chunk of the Onion's humor. E.g., "Congress Approves $4 Billion For Bread, Circuses"

https://politics.theonion.com/congress-approves-4-billion-fo...

And it's dumb. We're not setting hot lead into column inches anymore.

But we are trying to fit summaries into a limited screen real estate

In English the comma would be used between non-restrictive modifiers. However, this is a designation, and the industry or manufacturer denotes how the designation is to be structured. This is further compounded by being in a headline. Editors, and headlines in particular, use abbreviated syntax.

It confused me too when I first started working in the USA where it is common in headlines.

Using an ampersand requires only one more space than a comma but is unambiguous.