Was putting springs in on my mustang II ifs and something just doesn't look right. Looks like the.lower a arm sticks out further then the top spring mount cause spring to sit weird.

 

Sickler1
The spring does look strange sitting between the upper housing and the lower control arm. I don't have an answer for you as I am more familiar with the Jag IFS that I installed in my 51 F1.

I am sure there are those familiar with Mustang IFS that will get back to you. I just wanted to bump your question to the top. Good luck.
Dan

 

Have engine installed, bring bottom a-arms up till they are level and and measure spring length needed do not forget when front sheet metal installed will be more weight--

 

Thanks for infoiand pics info. try compressing the spring more.do you know what the correct spring length should be?

 

 

 

 

My Heidt's superide ll came with 500 lb coil over springs..

 

 

I used 375 lb springs with my big block, and they are a little stiff. Are you sure they werent quoting the rates for coilovers?

 

It can vary a bit depending on the angle of the spring. Vertical would need a higher spring rate. You can roughly work it out. Assuming you have a travel of around 4.0 inches and you want it to compress around 1.5 inches + 1 inch preload. Weight on front wheels is around 2000 lb say or 1000 lb per side. 1000 / 2.75 = 400 lb/in spring. If angle of spring = 15 deg, then factor it down by Cos (15) therefore 400 x 0.966 = 386 lb spring (approx). If you have an adjustable spring seat you can play around with the preload to get the right height Just be sure you get the best possible estimate of weight on the front wheels.

 

So did a bunch of measuring and came up with the spring perches need to be moved outward bout 1/2" on each side

 

How did you come up with that, this units are engineered for the application..

 

The directions say that the middle of the T-bolt hole should 32.75" away from the other T-bolt hole.mime almost an inch under that.instructions also to shim the spring perches to accomplish this measurement

 

Okay, surprised you'd have to add material. Yours is a different set up than what I have