I was courious the first time I saw that

Btw I'm talking about the Throttle body mounting surface if there is any confusion

Is this better worse than older models ?

Why did they do that ?

Thanks

They got rid of it when they deleted the cold start injector. If you look at a throttle body from pre-90 and one 90 - up, you will also see a difference on how they routed the IAC air.

85-88 is one style, and 89-92 is the other style. I dunno why it was changed, but the later style funnels the IAC air to the throttle body blades, while the 85-88 uses the triangle on the front of the plenum.