Bulkhead questions for my tank

[Mombo]

My SC Aquariums 120g Tank just arrived. New build thread coming soon :)

It came with 3 holes pre drilled that all fit 1in sch40 bulkheads.

I am thinking it might be a good choice to switch to Sch80 bulkheads. Can I still by 1in sch80 bulkheads and it will fit or do I need to get another size? Or will a sch80 not even fit at all?

What do y'all think I should do?

 

[Grey Guy]

The inside is a little less, but the outside is the same. 1" sch 40 and 1" sch 80 will fit in the same hole.

 

[Mombo]

Ah ok so I shouldnt have a problem at all switching.

Next question - Should I get slip x slip bulkheads? Or should I get one side with threads? With threaded do you still glue it?

Do I need to prime and glue everything I put together or do certain pieces not have to be glued?

 

[Mombo]

Also getting mixed feedback. The tank manufacturer said that sch 80 bulkheads need an extra 2mm to work.... Need to go buy a tester one and check it I guess.