C3 power steering question

I'm looking at firing the parts cannon at the power steering leak I have in my 81 Corvette. I've looked around and saw there are a few kits that include new high and low pressure lines in addition to the pscv and slave cylinder.

I've ended up pulling the trigger on a kit for 80-82, but I'm wondering if anyone can tell me what the differences are between the 63-79 and 80-82 kits.