Wrong:
he 77-81 5 speeds are almost just the 4 speeds with the extra gear and are considered "wide ratio".
The 82-83 5 speeds were designed as 5 speeds from the get go and are considered "close ratio".
If I remember correctly, ANY L series tranny will bolt up to any L series engine. The only differences are tranny or driveshaft length. If you get the transmission from a 2+2 the driveshaft will be longer, and if I remember correctly there are some oddball trannies that are a different length (though rarer then most).
If you want the 82-83 5 speed, I think it would be a straight swap using your driveshaft, as these later cares have an R200 and a different flange.