Need info on old Garcia Fly Rod, please help.

I have been given an old fly rod from my uncle..... It's a Garcia, Conolon, Companion #2537, 8 1/2 ft. fast taper.... It says "use C-HCH-GBF"..........

Does anyone know what weight line I should use based on the about info.?

My thanks for any help you can provide......

HCH is a 7DT...GBF is 8WF

here's a link to the conversion chart

http://www.hookhack.com/flylinesize.html

My thanks Jerry......