There are four key events in chapter 8 which create suspense. Firstly, Johnny's condition has deteriorated after his heroic rescue in the Windrixville fire. The greasers are concerned that Johnny's life hangs in the balance.
We see that Dallas has chosen to arm imself for the rumble: he is determined that the Greasers will settle the dispute once and for all. It is supposed to be a clean fight, and Dallas carrying Two-Bit's switchblade has echoes of Bob's attack on Johnny and Ponyboy, which had fatal consequences.
Ponyboy has still not properly recovered from the Windrixville incident and is hiding his poor condition in order to be allowed to fight. He also has a sense of foreboding of the events ahead.
Finally, it is revealed that Cherry Valance is acting as a go-between for the gangs. She is taking a great risk in sharing the Soc's tactics with the Greasers and she could be putting herself in danger.