[oemoilleaks]

I'm rebuilding my entire suspension setup right now and I was wondering if anyone knew off hand a couple of things.

I was thinking about buying and cutting the Mustang II springs from speedway motors (Mustang 2 springs - Speedway) for the front, and then cutting the front springs 1 coil, and moving them to the rear.

My big question is, what does anyone know off hand how much cutting 1 coil from the front springs that are going to the rear will do to the ride height?

I'm sure @RallyBob has all the suspension formulas I need

 

[RallyBob]

My big question is, what does anyone know off hand how much cutting 1 coil from the front springs that are going to the rear will do to the ride height?

The front springs are much longer than the rear springs. If you cut one coil from the front springs and put them in the rear, the car will be about 3” taller out back.

I don’t have specific formulas, but in general your starting point should be to make the front spring about one coil taller than the stock rears, then go from there.

 

[RallyBob]

Just to give you an idea.

In these pics, the shorter springs are fronts, and are 400 lb rate. They are almost 1/2 the length of stock front springs.

The rears are cut down front springs. They ended up being about 180 lbs at that length.

 

[oemoilleaks]

How tall are those 400lbs springs at uncompressed length?

 

[RallyBob]

How tall are those 400lbs springs at uncompressed length?

No idea. These are old photos, springs are no longer in my possession.

 

[oemoilleaks]

No idea. These are old photos, springs are no longer in my possession.

Fair enough!

I suppose the other alternative is to cut a coil off the fronts and leave them in the front, at least as a starting place.

The car has always had a weird backwards lean to it.

 

[Dropel]

I'm not sure what offset your wheels have, but be careful about the inner wheel well lips. On one of my Mantas I used Ascona wagon springs, and cut a coil or two (don't remember how many - it was 30 years ago). I had a couple different sets of wheels, the Ronal (BBS look alikes) rubbed so I had to use my minilites which worked, but I had to do some inner sheet metal mods because it would rub in full turn.

 

[oemoilleaks]

I'm not sure what offset your wheels have, but be careful about the inner wheel well lips. On one of my Mantas I used Ascona wagon springs, and cut a coil or two (don't remember how many - it was 30 years ago). I had a couple different sets of wheels, the Ronal (BBS look alikes) rubbed so I had to use my minilites which worked, but I had to do some inner sheet metal mods because it would rub in full turn.

I believe my wheels are 30mm offset. They're the GM stamped ATS classics.