Jbl 5504 enclose specs

[Bradley_38]

I want to build a pair of 5504 lf cabinets but I can't find any specs on the port diameter and port depth

 

[americanaudiophile]

Those won't be on any spec sheet. You would have to find someone that has the speakers to measure them.
If you want to exactly duplicate the sound of the 5504 and have the same JBL drivers then you would need those dimensions. If you are building a similar but not identical speaker you will get a better result by using Thiele-Small calculations to determine those. Will give you tighter bass that way.
http/www.mh-audio.nl/spk_calc.asp