I have a '56 F100 with a Mustang ll type front suspension. I have installed a 5.4 Triton with a 5 speed manual trans. The front springs are too weak and it sags quite low. Anyone know how to determine which springs to get (other than trial and error)? It looks like I should raise the front about 1.5-2.0 inches. The springs that are in it now came with the front end kit, I think it was just a guess from Heidts. Thanks for any help. Karl.

 

I looked up my paper work from when I purchased my MII I requested the coils to handle a 302 motor, but all the parts list shows it as are heavy springs. Was hoping it might show the pound rating to maybe show you what might be to light for your 390 motor. Looks like coil springs are rated in 25 pound implements.

 

I don't have a 390...I have a much lighter 5.4 Aluminum Triton engine...thought the light springs would be OK...wrong.

 

I wonder where I got the 390 from. I guess the brain is starting to slip just a little.