chevy 4 speed transfer case addaption

[factoryorange3]

i am hopefully getting a 73-87 k20 longbed frame and axles this spring. i have a heavy duty 4 speed transmission with the grany low gear, now i am wondering if those transmissions have a port where a transfer case can be bolted on to convert into a 4x4? this setup is destined to have a 350 smallblock with a 67 chevy cab on it with a flatbed. anyone that could help me out , it would be appreciated.