Finding Centerline 72 GTO GM A body to square up rear end
 

Hey Everybody,

I'm trying to find centerline on 72 GTO With stock frame for measurements

Would it be halfway between?

Outer rocker panels
Center of transmission or transmission crossmember
Center of stock frame

Thanks, Craig

Re: Finding Centerline 72 GTO GM A body to square up rear en
 

most cars I have seen have offset for steering box/engine clearance, not sure about GTO?

Re: Finding Centerline 72 GTO GM A body to square up rear en
 

I would drop a string line from 4 or 5 different places on each side of the frame, from front to rear. Obviously use the same point on each side - suspension mounting points, factory locator holes, etc. Mark on the floor and find the center. If they all don't fall on the same line, double check your locations. And hope the car hasn't been hit.

Driveline is offset to the right. Don't recall the measurement but should be parallel with the chassis centerline.

Re: Finding Centerline 72 GTO GM A body to square up rear en
 

If you're trying to find centerline of the body, use a plumb bob from the trunk lock to the floor and the center of the grill to the floor.

Re: Finding Centerline 72 GTO GM A body to square up rear en
 

Re: Finding Centerline 72 GTO GM A body to square up rear en
 

A nice way to do it is to use the holes in the bottom of the frame shown in the link above. Then, you can drop multiple points down with a plumb bob to the ground on both sides. Measure across to get centers than take a string or laser and draw the centerline thru them.

Re: Finding Centerline 72 GTO GM A body to square up rear en
 

Pretty sure the engine centerline is offset to the pass side by 5/8".

Re: Finding Centerline 72 GTO GM A body to square up rear en
 

I seem to remember that the factory shop manuals had those frame directions in them. If I am recalling correctly then the GTO material should be easy enough to find.