Are glock parts interchangble between generations. For example, will a glock 17l 2nd generation part fit or be able to be used in a 3rd generation 17l and vice versa?

Tricky question... some parts are some parts aren't.. would have to be more specific. 

IFAIK, its the larger design of the fram and grip that's changed between gen 2 and 3. Gen 4 and 5 have completely different slides, but some internals may be the same.

Just now, JackDaWack said:

Tricky question... some parts are some parts aren't.. would have to be more specific. 

IFAIK, its the larger design of the fram and grip that's changed between gen 2 and 3. Gen 4 and 5 have completely different slides, but some internals may be the same.

This actually answers it. I was looking between 2 and 3 parts. If they weren't 100 percent compatible then i don't wanna take on the project. Thank you