I'm finally getting to work on my 67 Shelby GT 500 after 33 years sitting in my garage (life's funny ain't it?).
It sits kind of low in the back. What's the correct ride height front and back, and where are the measurements taken?
Typically they did have the rear a bit lower than the front, see attached image from promotional film with Carroll Shelby...
also a link to a previous thread that touches on the topic...
https://www.saacforum.com/index.php?topic=16512.msg134391#msg134391
The 67-8 Shelby GT's use the Ford "Competition" suspension. Basically what it does is sits the rear lower then a standard Mustang and from the side view give it a speed boat look.
I personally don't like it or the very short rear axle travel it gives. Ironically the car is rated to take rear passengers but if you put anyone back there the car will sit on it's travel stops.
The simplest way to fix this is to add an additional top spring leaf to the stock spring. It will give you better feel, road handling and look.
IF you do your homework you will notice that many, if not all, of the R models had this modification done to them as well. It works very well particularly with lowered front a-arms.
To follow-up on what Doug said, IF you do the front-end drop, the handling dramatically improves, but you have to drill holes in the front shock towers, and obviously re-align the front suspension. It also makes the car sit more level if the speed-boat look bothers you.
I just bought a 67 GT500 and that's the first thing I'm going to address. My understanding however was that Shelby already dropped the A-arms one inch. Not true ?
Does anyone know what the coil spring ratings are with these cars? We used to drop in shortened 620 lb springs in stock 66/67 mustangs along with dropping the A-arms one inch plus Koni shocks and that would result in an almost perfect lowered stance.
Quote from: fastek on August 05, 2023, 12:13:48 PM
I just bought a 67 GT500 and that's the first thing I'm going to address. My understanding however was that Shelby already dropped the A-arms one inch. Not true ???
Does anyone know what the coil spring ratings are with these cars? We used to drop in shortened 620 lb springs in stock 66/67 mustangs along with dropping the A-arms one inch plus Koni shocks and that would result in an almost perfect lowered stance.
67 didn't have lowered A arms .In fact from the factory 67's set a little lower in the back then the front. Shelby stopped lowering the A arms after about 1/3 of 66 GT350 production was built.
Consider that if you are going to lower your a-arms and it was not original to the car, 1" drop is not optimum. 1-1/2" is.
1" was used since it was the most they could go without binding up the ball joint which was a Ford warranty issue.
If you go 1-1/2", you need to space the ball joints with wedge shaped spacers and also consider that ANY lowering of the front a-arms makes the car bump steer radically.
Isn't it fun asking questions here? ;D
At this point, it is all about opinion. I like the lower front with a slight rake. Others like the boat effect. some like it level. Do what you want. I don't care. my 66 is horrible, it is going so up hill it is rotten.I cannot even get anyone to do the a arm trick. BUT I will. Just do what you like and "blank" the rest. Last I knew, I sleep with not judges.
Quote from: shelbydoug on August 05, 2023, 03:26:51 PM
Consider that if you are going to lower your a-arms and it was not original to the car, 1" drop is not optimum. 1-1/2" is.
1" was used since it was the most they could go without binding up the ball joint which was a Ford warranty issue.
If you go 1-1/2", you need to space the ball joints with wedge shaped spacers and also consider that ANY lowering of the front a-arms makes the car bump steer radically.
Isn't it fun asking questions here? ;D
I've seen a few 1" drop kits and a 1.75" kit but no 1.5" . Aside from the guy in Utah which I think you mentioned doesn't do that anymore ... do you know any suppliers for 1.5" drop kits? Thanks ....
No. It was Boyd in Utah. Pro Sport I think his company name was?
I know that he varied the kit from 1.5 to 1.75 but to be kind I'd say "he is a very unique individual".
I would have to measure my kit and it might have been a 1.75 but I'm not sure at the moment. I did that install thirty some-odd years ago.
The optimum drop number didn't come from him but was debated some time around the time I bought it.
I have his bump-steer eliminator kit in the car also.
I think that it is the concept that is significant not necessarily the numbers.
The bigger drop and the results have real results.
I'd suggest that you talk to someone at Cobra Automotive in Connecticut about it. Curt Voght has a lot of suspension components that he developed for racing and he is much easier to talk to and work with.
Knowing him I'd predict that he has built and tested all of the variations and can quote you technical results of which is the best way to go. I suspect that he and Boyd might be at odds on this but Curt wasn't doing the bigger drop at the time. Just Boyd.
I am also using the 1-1/8" bar in the front and an additional big leaf in the rear. The car is very easy to drive and handle. A kid could drive it fast and park it simply too.
I used Global West control arms and they came with a template to relocate the mount points by 1 3/8 or 1 1/2", I don't remember which.
fwiw
Quote from: mikeh on August 06, 2023, 12:28:58 PM
I used Global West control arms and they came with a template to relocate the mount points by 1 3/8 or 1 1/2", I don't remember which.
fwiw
I think that the Global West a-arm eliminates the necessity for the ball joint wedge?
If you use the Ford a-arm, you need the ball joint wedge to prevent the ball joint from jamming.
Part of the kit from Boyd includes the wedge. It also include a special CNC machined templet and flat washers that seat precisely against the stack of uneven Ford assembled uprights. Those never were intended by Ford to have this kind of a change so are necessary.
The templet stays in place and also acts as a mounting reinforcement.
You can't do a drop this big without those specially machined pieces which likely were also a reason for only a 1" drop by "Shelby". That wasn't a Shelby designed drop. It came from Ford Engineering.
There is a difference in how you drop the 65-6 and later cars. There are two different templets for that. I presume that exists in order to REDUCE the bump steer?
In my case I did my 68 GT350 first. I used the 67-8 templet and wound up with EXCESSIVE bump steer.
At the time there were no "bump steer elimination" kits made by anyone. Boyd was the first one to offer that and it works well. I don't know if it entirely eliminates the bump steer since I never measured that but the addition of 620 pound "Boss 302 Competition" coil springs and switching to radial tires virtually eliminated the feel of bump steer.
It was so extensive with the Goodyear bias ply tires that the car would change lanes by itself just driving down the road and hitting the seams in the concrete joints. It would jump 1/2 a lane at like 70mph. So be aware that you need to have "bump steer elimination" provided for in your budget.
That drrawing of the templet originally appeared in the Maque drawn by Jeff Burgy. A copy of that is on Tony Branda's web page...somewhere. Possibly on the SAAC home page as well.
You also need a 17/32" drill bit for the 1/2" shoulder bolts on the a-arms.
Great stuff Doug ...... thanks much for sharing your wealth of info.
The OP first post asked about the "correct" ride height which in this context means stock factory. This is not meant to impose what each individual should do to his or hers car just answer the OP's question . The thread seems to have changed direction into reply's of what others think are best. Hopefully the information provided so far will be enough so others can make a informed decision on what is best for each individuals situation.
😉 +1
Quote from: Bob Gaines on August 08, 2023, 05:17:40 PM
The OP first post asked about the "correct" ride height which in this context means stock factory. This is not meant to impose what each individual should do to his or hers car just answer the OP's question . The thread seems to have changed direction into reply's of what others think are best. Hopefully the information provided so far will be enough so others can make a informed decision on what is best for each individuals situation.
Absolutely. 8)