GO:0102555:   octanoyl transferase activity (acting on glycine-cleavage complex H protein)
Catalysis of the reaction: [glycine cleavage system lipoyl-carrier protein]-L-lysine + OCTANOYL-ACP = H+ + a [glycine-cleavage complex H protein] N6-octanoyl-L-lysine + a holo-[acyl-carrier protein]