Shelby Arning Drop with Stock Parts?

[gnatsum 12]

Hello everyone. I am replacing the front suspension on my 1969 Mustang Mach 1 using all stock replacement style parts. I would like to do the Shelby drop and lower the upper control arms by 1 inch. My question is - can this be done using all stock style parts? Or will any of the other components need to be modified or changed? Also, will this cause any clearance issues with the tires? I am using 14x7 Magnum rims with 225x70x14 Cooper Cobra radial tires. One last question: how dangerous is it to remove and reinstall the coil springs? I have heard stories but it seems like it shouldn’t be too difficult if you are careful. Thanks for your help!

[latoracing 257]

Yes, stock parts will work fine without interference with your wheels and tires.

As long as you have a good spring compressor, you shouldn't have any issues removing and replacing the springs. 

 

[Ridge Runner 1,226]

Just make sure that spring compressor is seated in the spring properly 

[1969_Mach1 335]

Make yourself a template from something like 1/8" or thicker steel.

- Drill two of the bolt holes in the template the correct size to bolt to the existing control arm bolt holes.

- Then drill the two new 1" lower holes in the template only 1/8" diameter for a pilot drill.

- Bolt the template in place, drill two new 1/8" diameter holes in the shock tower using the new 1/8" template holes as guides

- Remove the template and finish drilling the new holes to the final size in a couple of more steps.

[lanky 44]

something I wish I was told before I did this, but I can also blame myself for not thinking about it, is not only lower control arm holes but relocating them slightly rearward to increase caster without the wheel being pulled too far forward in the wheel well.

[det0326 202]

1 hour ago, lanky said:

something I wish I was told before I did this, but I can also blame myself for not thinking about it, is not only lower control arm holes but relocating them slightly rearward to increase caster without the wheel being pulled too far forward in the wheel well.

exactly what i was going to suggest Lanky. I did this to mine and also set the shaft in control arm forward a thread or two. all this made the grease fitting to close the the shock tower so I plugged the original hole so I positioned everything the way would be torqued down and marked the nut hex flat facing out. took back apart and drilled and taped the hole. With this modification and lower control arm pulled forward as far as I could without tire rub on valance I got 5 degrees caster. I had CPP intergral steering box similar to Borgensen and the car drove awesome.

[gnatsum 12]

Thanks everyone

[gnatsum 12]

One more question: I removed one of the coil springs and after decompressing it, I compared it to the replacement spring I bought from CJ Pony Parts. The new spring is about 3/4” longer (and almost one full coil longer) than the original. Note that the springs I bought are for a small block. The original engine was a BB 390 but it was removed by the previous owner. After I bought the car I installed a SB 351W. The old springs appear to be original since all of the other suspension parts also look untouched. The spring pitch is the same on both coils. Thoughts?

[1969_Mach1 335]

Try the new springs as they are.  Lowering the upper control arms will lower the front of the car almost 1".  That 3/4" longer new spring might work out okay as it is.  If it's too low they make thicker coil spring upper insulators.  If it's too tall, you can trim the coil springs.

Did you compare the wire diameter of the new and old springs and also the number of coils?  Both of those items affect the spring rate.

[gnatsum 12]

Thanks. I went back and checked the wire diameter is a little bit bigger on the older springs. The number of coils is the same.

[1969_Mach1 335]

It sounds like the old springs were a little stronger, which makes sense.  All you can do is try the new springs and see how the car sits.

[unilec 57]

And make sure you have a decent internal spring compressor, I have been thinking about making my own, lot of rubbish out there now.

[gnatsum 12]

I am converting from power steering to manual steering. I removed all of the power steering componentry except for the Pitman arm and the idler arm. Those look very difficult to remove because of my headers. Would it be possible to reuse the idler arm and Pitman arm with the new manual steering center link?

[Kris 90]

The pitman arm will be reused but the idler arm is different if your going with a manual steering center link. 

[aslanefe 356]

As afr as I know, both pitman and idler arms are different between power and non-power steering.

[Grabber70Mach 113]

On 9/24/2020 at 2:31 PM, aslanefe said:

As afr as I know, both pitman and idler arms are different between power and non-power steering.

That was my impression as well. 

[Kris 90]

You guys are correct, not sure what I was thinking. The manual steering pitman arm has a stud like a ball joint and the power steering one just has a hole that the stud on the control valve connects to. 

[JayEstes 176]

I used a template to move the holes for the Shelby/Arning drop.  I put in all stock suspension after that.  All the comments above are good on the spring compression.  I did it, but it is a very dangerous spring.  If you don't have that thing completely under your control it can really hurt you.  I think internal spring compression is the only way to go - the external spring compressors have a way of being perfect when you put them on, but as the spring is compressed it changes shape, causing the grip to change - this can lead to an unexpected slip.  I put on 15x8 wheels (4.25in backspace: https://www.summitracing.com/parts/crr-61815?seid=srese1&gclid=CL2x2NXE3cMCFYk2gQodPGsAOA) with 235/60 Cooper Cobra white letter tires.  With those wheels tires, the stock suspension, the drop, the stock spring height, I have not had a single wheel rub.  I'm very happy with the setup. 

The 225/70 tires though are 1.3in larger diameter: https://www.tacomaworld.com/tirecalc?tires=235-60r15-225-70r15, so It is not clear that system won't have a tire-rub issue. You might be able to modify the backspace to make it okay - I'm not sure.  

Hope you find this useful.

Jay

[aslanefe 356]

1 hour ago, JayEstes said:

I used a template to move the holes for the Shelby/Arning drop.  I put in all stock suspension after that.  All the comments above are good on the spring compression.  I did it, but it is a very dangerous spring.  If you don't have that thing completely under your control it can really hurt you.  I think internal spring compression is the only way to go - the external spring compressors have a way of being perfect when you put them on, but as the spring is compressed it changes shape, causing the grip to change - this can lead to an unexpected slip.  I put on 15x8 wheels (4.25in backspace: https://www.summitracing.com/parts/crr-61815?seid=srese1&gclid=CL2x2NXE3cMCFYk2gQodPGsAOA) with 235/60 Cooper Cobra white letter tires.  With those wheels tires, the stock suspension, the drop, the stock spring height, I have not had a single wheel rub.  I'm very happy with the setup. 

The 225/70 tires though are 1.3in larger diameter: https://www.tacomaworld.com/tirecalc?tires=235-60r15-225-70r15, so It is not clear that system won't have a tire-rub issue. You might be able to modify the backspace to make it okay - I'm not sure.  

Hope you find this useful.

Jay

Hi Jay, how would 245/60/15 fit on front with your rim, do you have ample clearance with 235s?

[EastYorkStang 68]

On 9/24/2020 at 7:37 AM, gnatsum said:

I am converting from power steering to manual steering. I removed all of the power steering componentry except for the Pitman arm and the idler arm. Those look very difficult to remove because of my headers. Would it be possible to reuse the idler arm and Pitman arm with the new manual steering center link?

I used one of these when I converted mine to manual steering.

https://www.cjponyparts.com/manual-steering-adapter-mustang-1967-1970/p/MSA/

Never changed the centre link or any other parts.

[JayEstes 176]

8 hours ago, aslanefe said:

Hi Jay, how would 245/60/15 fit on front with your rim, do you have ample clearance with 235s?

It's hard to say.  It's much closer to the same but still about 0.5in larger.  Since I haven't had any tire rub issues (not once in 10K mi) I guess I have "ample" clearance - but that's pretty subjective.  Couple of pics to try and quantify:

 

Bear in mind I have STOCK springs, and I put KYB gas-adjust shocks all around (which are fantastic BTW),  arning drop with stock suspension arms/spindles.  I figure another 0.25in larger on either side on that tire is probably not a problem, but I am not showing it at full wheel turns either.  IDK - I like what I have and I wouldn't change a thing - it never ever gives me problems.

One more that might give you pause:

[aslanefe 356]

54 minutes ago, JayEstes said:

It's hard to say.  It's much closer to the same but still about 0.5in larger.  Since I haven't had any tire rub issues (not once in 10K mi) I guess I have "ample" clearance - but that's pretty subjective.  Couple of pics to try and quantify

 

Bear in mind I have STOCK springs, and I put KYB gas-adjust shocks all around (which are fantastic BTW),  arning drop with stock suspension arms/spindles.  I figure another 0.25in larger on either side on that tire is probably not a problem, but I am not showing it at full wheel turns either.  IDK - I like what I have and I wouldn't change a thing - it never ever gives me problems.

One more that might give you pause:

 

Thanks for the pictures; how much clearance to frame rails do you have when the steering is at full turn? Also, how much clearance to upper control arm? The reason I am asking is, I found some new 245/60/15 tires for a real good price and was thinking of buying them for all 4 corners of my 70 Grande if they fit to fronts.