Our Mustang II springs come in rates from 275 thru 425 and in 13.5” free height/length. They will require cutting to the necessary length on the majority of applications. For the heavier vehicles such as full size pickup trucks and fat fendered cars the spring rate used will normally be in the 350-400 range. With Small Block and automatic a common rate is 375 to 400 and with the addition of A/C or a big block you will need to compensate for the additional weight and go to the next higher rate. Frame boxing and plating, accessories, and fuel tank size all play a part in selecting spring rate. When vehicle is sitting at ride height ready for test drive the lower control arms should be parallel with the ground or pointing down at a slight angle on the outer ends. The springs will settle some in the first couple of hundred miles so allowance for this should be made.
- Powder coated gloss black
- 13.5" spring length
- Use the spring chart below to select proper rate
Use the following chart to select your rate:
- 1200 lb. Front End Weight = 275 Rate Spring
- 1300 lb. Front End Weight = 300 Rate Spring
- 1400 lb. Front End Weight = 325 Rate Spring
- 1500 lb. Front End Weight = 350 Rate Spring
- 1600 lb. Front End Weight = 375 Rate Spring
- 1700 lb. Front End Weight = 400 Rate Spring
- 1800 lb. Front End Weight = 425 Rate Spring