if you wanna drop a 4g63 or a 4g64 into a 5G basically what you need to do is get a late model evo or lancer ,you might be able to get a 4g64 out of say a summit wagon , not sure how those mount tho.
you might run into some problems with the tranny on the 4G64 wich is od since its basically a stroked version of the 4g63