Sorry for the late replies as I am very busy nowadays, actually Ishmael being the sacrificed son is mentioned by name in the Sunna, as for the Quran, although it wasn't mentioned that the sacrificed son is Ishmael, but the context is clearly talking about the action of sacrifice then it moves to the birth of Isaac, and it's well known that Ishmael is older than Isaac:
99. He said: "I will go to my Lord! He will surely guide me!
100. "O my Lord! Grant me a righteous (son)!"
101. So We gave him the good news of a boy ready to suffer and forbear.
102. Then, when (the son) reached (the age of) (serious) work with him, he said: "O my son! I see in vision that I offer thee in sacrifice: Now see what is thy view!" (The son) said: "O my father! Do as thou art commanded: thou will find me, if Allah so wills one practising Patience and Constancy!"
103. So when they had both submitted their wills (to Allah., and he had laid him prostrate on his forehead (for sacrifice),
104. We called out to him "O Abraham!
105. "Thou hast already fulfilled the vision!" - thus indeed do We reward those who do right.
106. For this was obviously a trial-
107. And We ransomed him with a momentous sacrifice:
108. And We left (this blessing) for him among generations (to come) in later times:
109. "Peace and salutation to Abraham!"
110. Thus indeed do We reward those who do right.
111. For he was one of our believing Servants.
112. And We gave him the good news of Isaac - a prophet,- one of the Righteous.
http://www.islam101.com/quran/yusufAli/QURAN/37.htm
The Jews of course wanted to have the honor of being the sons of Isaac, that's why they corrupted that verse.