I'm installing a Blox water temp adapter inline with the upper radiator hose to run the water temp gauge and was wondering what size shoud I get.

The upper radiator hose size for a 91 DA is 30mm.. so do I get a 30mm adapter or a 32mm?

I'm thinking 30mm since it's the exact same size but it might be hard as hell to get on or should I go with a 32mm and use a clamp to clamp it tight?

 

dude its 2mm...its not going to matter. go with the 32 if you are really worried about the 30 being too tight

 

Haha yeah I know just wanted to be sure so it doesn't have a reason to leak under pressure even with a clamp.