The 1979 O'DAY specs (I think this is what is being refered to by Ed K), give the following lengths/sizes;
Jib Sheet 3/8" dia. x 48' That is for the working jib (approx 100%) and would be tied through the clew of the jib resulting in approx. 24' per side.
Main Sheet 3/8" dia. x 40'
Genoa Sheets 3/8" dia. x 60' (again tied through clew and thus 30' per side.
All lines above would typically be of Double-Braided Dacron/Polyester.