I read that a Y-Head Corvette has a cargo weight cap of; Weight Cap: 3,300 T and a Volume Cap: 2,800 m³.
I read that a GRZ-6B Wrecker has a weight of; Weight: 32 T Volume: 625 m³.
That would imply that 4 Wreckers would fit on a Y-Head.
I am commander/pilot of both Ships and am in the same location and yet I get no "Dock" options when I try to load the Wrecker onto the Y-Head.
I have loaded YT-1210s on Bayos before so I assumed a Wrecker would load on a Y-Head.
That's probably an old description. A long time ago, it was a CP ship, and it did have a docking bay. In fact, there are still 2 in the combine that do have Docking Bays. One is owned by Jeb`el Ras, and I forget who owns the other one...
Anyway, it's best to check the little boxes on the rules page for that ship, it shows what capabilities it does and doesn't have. Descriptions can be old, or just make things up.