Engine size

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Oct 5, 2011 | 03:28 PM

Shalamara

Thread Starter

March 2013 ROTM

Joined: Jul 2011

Posts: 415

From: Culver, Oregon

ROTM Winner's Club

Engine size

Why did GM build 3 motors so close together in size? 302ci, 305ci, and the 307ci

Oct 5, 2011 | 07:04 PM

z28pete

Tech Droid

Joined: Aug 2005

Posts: 9,215

From: North East PA

The engines are similar in displacement, but the internal dimensions are entirely different.
302 4" bore X 3" stroke (Free breathing high revver)
305 3.74" bore X 3.48" stroke (Built to meet pollution control)
307 3.87" bore X 3.25" stroke ( No good reason for it)