If the 465 is a 32spline version (1 tons of the 80's and NP208's) then you'll need to simply drill and tap the face of the NP203 to match the "round" factory adaptor.
OR
Go find a SM465/NP203 adaptor (rare) and then buy the ORD "short" 32 spline 465 shaft.
Option 1 is cheaper, option 2 is shorter. all depend on your driveline length.