What was the record for the phone marathon in The Pigman?

Dennis holds the record for the longest conversation in the phone marathon game.  He had once picked out a woman "who lived alone and was desperate to talk to anyone".  Dennis told the lady that he was calling because he had heard that she gave good advice, and he had a problem concerning a "hideous skin disease" which was certain to lead to his death if he did not find a cure.  According to Dennis, a rat had bitten off his nose when he was a baby, and skin grafts had not taken.  Dennis had been able to keep the woman discussing his problem on the phone for two hours and twenty-six minutes, which was the record for the longest conversation in the game.

The phone marathon is a game that John, Lorraine, Dennis, and Norton sometimes play when they are bored.  They take turns closing their eyes as they run their fingers down the phone book, and they must call the number at which they randomly stop and try to keep the person they call engaged in conversation for as long as they can.  On Wednesdays, the group can play at Dennis' house because his parents are not home, and on Sundays they use the phone at Norton's place because his parents do not mind if they gather at his house.  John and Lorraine's houses are off-limits for the game because both their parents have issues with their children tying up the phone in this manner.

It is Lorraine who chooses the Pigman's name from the phonebook during a game of phone marathon.  She had actually cheated a little bit, peaking when she was going through the book; she had chosen the Pigman because he lived on nearby Howard Street, and she had already thought up a ruse by which she could start up a conversation with him (Chapters 3-4).