[Johnson] 1614 vs 6L6

[Rick Brashear]

I know this is an old discussion, however, I am old too and forgetful.  
So, indulge me, please, as I ask for a comparison of these two fine 
tubes when used in a Johnson Ranger I.  I know the 6L6 will work and I 
think it works pretty good.  However, I think the issue is longevity.  
Has anyone had experience with the use of both tubes in a Ranger?  
1614's are getting harder to find and more expensive. 

Any thoughts?

Thanks,
Rick/K5IZ