Swapping 203 for 205 on th400

[ncl]

Ok currently my 78 K20 has no transfercase in it. My uncle took it out and installed a 2wd tailhousing on the tranny and made it a 2wd truck. What I want to do is put a transfercase back on it. The truck originally had a np203 but was thinknig about a np205 instead. Is the length of the ouput shaft different on TH400's that came equipped with np205. Just need to know if this wuold be a easy swap by just changing the adapter and tcase. Also anyone have any pics of th400 np203 combo in the truck I need to know what kind of supports I should be getting if I decide to stick with the np203.
Any info would be greatly appreciated.