CLASS RACER FORUM - View Single Post - Finding Centerline 72 GTO GM A body to square up rear end

FED 387 · 09-18-2025, 02:36 PM

GM started with the centerline of the car then offset the diff 1/2 inch to the right---because of all the available engine combos for this body they moved the Big Block engines around with engine mounts that were unique to that particular engine used ---small blocks used the centerline of the car and maybe a big block Olds might use a different motor mount on the frame than a small block Chevy would use.. It all depends on the specific engine being used whether it is a Buick- Olds -Pontiac or Chevy --SAME frame just different engine mounts and/or holes on the frame to correspond to the particular engine being used NOT the mount that bolted to the engine---that's where the off set comes in--- its the frame mount not the engine mount---Make sense?? FED 387

09-18-2025, 02:36 PM	#15
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,429 Likes: 563 Liked 336 Times in 183 Posts	Re: Finding Centerline 72 GTO GM A body to square up rear en GM started with the centerline of the car then offset the diff 1/2 inch to the right---because of all the available engine combos for this body they moved the Big Block engines around with engine mounts that were unique to that particular engine used ---small blocks used the centerline of the car and maybe a big block Olds might use a different motor mount on the frame than a small block Chevy would use.. It all depends on the specific engine being used whether it is a Buick- Olds -Pontiac or Chevy --SAME frame just different engine mounts and/or holes on the frame to correspond to the particular engine being used NOT the mount that bolted to the engine---that's where the off set comes in--- its the frame mount not the engine mount---Make sense?? FED 387