hey i live in northport!
um you can try this guy, i got his number from a friend. ive never been to him and am not really sure if hes "for hire" hes kinda a shade tree mechanic but he knows his ****. if he wont do the work for you im sure that hell know someone on the island who will. i think hes either near mastic or the hamptons, but i might be wrong. his name is "mopar" Tom his number is (631)793-6415 hes helped me out a bit and he also usually has some parts. good luck.
-marc