Crankcase ventilation.

i've 't'eed the pcv and servo hoses together more than once with no issues. i keep the 't' fairly close to the carb. carb n umbers on a holley to id it are stamped on the front of the choke horn, your diagram shows it as list number and production date. take your filter spacer ring thingy off and you'll see the numbers. the ones you showed are just on the metering block.
neil.