Have you got these backwards? Dark /l/ is before back vowels and word finally.
Also, there is no closure at the hard palate, is there? Dark /l/ is velarized, so its primary articulation is still alveolar, but the back of the tongue is approaching the velum as well.
Maybe the articulation of dark /l/ is more variable than I thought./'litl/lateral plosion (some people put a schwa in there, but I don't - unless I'm imitating the Goon Show - Bluebottle certainly said /'litəl/, but he also labialized the final /l/.)
needle nardle noo.