TR4ffic

Hi All, I'm after a bit of advice if I may... I'm having to replace the seals on the bottom of the carbs, where the float chamber attaches. I have the arrangement on the right in the image - Stud (123) and the nut (120). New seals received from Moss... Questions is: How tight should the nut be done up? After a long time standing idle (The TR, not me!), on trying to start it over the weekend, discovered fuel leaks from both carbs and the nuts weren't tight ...tightening them didn't stop the leaks and could almost have made them worse! Many thanks in advance Nick