Would lebron have made it to 7 straight finals if his Miami Heat team and cavs team were in the western conference?

No not seven maybe 4 or 5

Assuming you move the opposing finals team to the Eastern Conference, then its possible

If Lebron was on a Western Conference team like the Clippers (Blake Griffin/Chris Paul), he could definitely make 7 straight finals

Of course not teams in the West beat him half of those years