Rear end sag

[68krrrr]

What the preferred look on the way a GT500 should sit should it look level or was there  a natural rear end sag from the factory like i see a lot of ,taking measurements from top of fenders to ground I'm 25" 3/4 inches in front & 25" 1/4 in back with goodyear speedways so 1/2 in lower in the back

[Bob Gaines]

What the preferred look on the way a GT500 should sit should it look level or was there  a natural rear end sag from the factory like i see a lot of ,taking measurements from top of fenders to ground I'm 25" 3/4 inches in front & 25" 1/4 in back with goodyear speedways so 1/2 in lower in the back

The measurements are the same for regular Mustang as they are for the Shelby taking into consideration tire size difference. The factory designed the car to be slightly lower in the back then it was in the front. If you don't like the factory way then given it is your car to do with as you choose then no one can stop you from adjusting the rake of the car as you choose. With that said if entering in a concours event the expectations are for the factory way.   

[68krrrr]

Thanks Bob your quick responses are always appreciated

[67 GT350]

No comment from me, I know what I like and it would not be concourse. (I guess that is a comment).

[shelbydoug]

What the preferred look on the way a GT500 should sit should it look level or was there  a natural rear end sag from the factory like i see a lot of ,taking measurements from top of fenders to ground I'm 25" 3/4 inches in front & 25" 1/4 in back with goodyear speedways so 1/2 in lower in the back

The measurements are the same for regular Mustang as they are for the Shelby taking into consideration tire size difference. The factory designed the car to be slightly lower in the back then it was in the front. If you don't like the factory way then given it is your car to do with as you choose then no one can stop you from adjusting the rake of the car as you choose. With that said if entering in a concours event the expectations are for the factory way.

I thought that the issue was that Shelbys got the Ford "Competiton" rear spring? That spring has a different arch which sits the rear lower?

I don't think that all regular production Mustangs got that "Competition" spring?

Am I incorrect?

[Bob Gaines]

What the preferred look on the way a GT500 should sit should it look level or was there  a natural rear end sag from the factory like i see a lot of ,taking measurements from top of fenders to ground I'm 25" 3/4 inches in front & 25" 1/4 in back with goodyear speedways so 1/2 in lower in the back

The measurements are the same for regular Mustang as they are for the Shelby taking into consideration tire size difference. The factory designed the car to be slightly lower in the back then it was in the front. If you don't like the factory way then given it is your car to do with as you choose then no one can stop you from adjusting the rake of the car as you choose. With that said if entering in a concours event the expectations are for the factory way.

I thought that the issue was that Shelbys got the Ford "Competiton" rear spring? That spring has a different arch which sits the rear lower?

I don't think that all regular production Mustangs got that "Competition" spring?

Am I incorrect?

Competition suspension leaf springs only came on cars with that option. The leafs are all marked different (67 are  AM,AR) most likely to indicate the spring rate. The competition suspension spring has the same arch when I put it next to a regular Mustang leaf when putting them upside down standing with the bushing and shackle end on the floor. I would assume from that they would sit similar on the car.

[deathsled]

Doesn't sitting lower in the back give the car an advantage in a drag race?  Faster off the line?  The 500s are a pretty good Shelby for the straight line crowd (and I am as much a fan of drag cars as road racers).

[67 GT350]

The rear end being in a "sag" position helps with off the line starts, as the weight of the car shifts back to aid in traction, (in theory). ALSO, for overall aid in stopping, the backend will not rise up on a hard brake, the frontend will go down as well to help the car stop better, (in theory). In reality it seems that 67's were set up different than 68's.
Not a fan of the "sag" look. Not a fan of the "Jacked up reared" look also. I feel that a very slight "rake" makes the car look better standing still and while driving. A sagging car, any year, any brand, any model, just does not look good, (to me).
Probably yet another reason to not want a "concourse" car. (for me).

[gt350hr]

  For drag racing , a nose up tail down "static" attitude is NOT the best for traction UNLESS you are racing on stock tires. With a modern slick , the nose down , rear up attitude puts more weight "load" on the rear tires as the front end rises ( with no tire slippage). It also allows the front end to settle back to the nose down attitude and "cut" through the air better at speed. A nose up attitude lets too much air under the car and hurts top end speed. 54 years of doing it has given me some experience on the subject. LOL
     "In the day" and on the lot or in the showroom , '68s were at best "level" and most often were lower in the rear.  I never saw one with a nose down attitude when it was new. '67s ( again , in the day) often had a slight nose down , or were level . I don't recall any of them lower in the rear when new. Spring sag was pretty common after 6 or 7 years on all Mustangs back then. Well IMPE anyway.
   Randy

[Bob Gaines]

The 67 assembline manual gives measurements that indicate that a car from the factory with the GT or Improved handling package (competition suspension?)is specified to be 1 inch higher in the front then in the back with a small plus or minus possible variation. That is a small amount and may look level to many casually looking.

[deathsled]

Thanks for the info Randy. I will defer to your expertise on the subject and your explanation was interesting for me.

Richard E.

[honker]

I thought that this thread was about something that happens as we age   

Mike

[gt350hr]

   +1 Bob , with the kickup in the body line , they do look level. The wheel opening in the rear certainly could be an inch lower and still have the look. The spoiler fools the eye too. ( well mine anyway).

[6T6/7]

My car has Eaton Detroit replacement springs and appears to me to set pretty level.  But, out of curiosity, I took measurements from the floor (flat garage floor) at the underside of forward and aft end rocker.  The aft was slightly higher (by 3/16 in) than the front.  However, when I measured from the floor to the top of the wheel openings, I found the rear wheel opening to be lower by 1/2 in. than the front.  Granted, these are dimensions for my particular car, but it tells me the rear wheel openings come down further than the front.  Also, the rear of the car is not necessarily supposed to set lower just because the rear wheel opening height dimension is supposed to be smaller than the front.  For some reason '67s and '68s in particular seem to be susceptible to rear sag, which may have contributed to that reputation.