I'm running into this same problem now. Got Tein Monoflex coil overs but the springs are too wide to fit the SPL Midlinks. Apparently even the stock springs are too wide for the SPL Midlinks. You have to have 2.5 inch diameter springs to work with the mid links from SPL. Tein makes this size but of course it takes 3 months to get them from Japan. Lovely. Will have to use a different brand.

You can always get some Swift Springs to fit your SPL mid links. ;)

Swift Springs USA

2.56" ID springs available in lengths from 5" to 11". Various spring rates as well.

That is what I did. Got the Swift 2.5 inch springs in 12K, 7 inch length.

Hey Ent, had a question regarding the spring length selection on the SPL midlink.

Do you have to raise the midlink the full 3"?

How far from OEM does that leave you lowered, by my calcs that must be almost 2.5".

Well I did not do the install myself so this information is based on conversations I had with my installer along the way. I think the location of where the spring sits in the SPL mid link is higher than the stock mounting location. So he measured it out with adjustment in the middle on the SPL mid link and there was about 7" of space so we went with the 7" spring length. I ended up with a 0.5 inch drop overall from the Nismo spring that was on there before (which I believe is about 12" length). This was also the spring length recommended by SPL to keep stock height. So I can still lower the rear an additional 1.5 inches (total 2 inch drop) or raise it up 1 inch higher than it was before. Does that help?

This does help.

I have a 2010 370Z touring roadster with sports package, convertible. I recently got all of the below and ran into issues on height for the rear.

KW Variant 3 Coil-overs
Hotchkis 370z front sway bar
SPL PRO Front Upper Camber/Caster Arms
SPL PRO Front End Links Spherical

SPL TITANIUM Rear Mid Links
SPL TITANIUM Rear Camber Arms

SPL Eccentric lockout kit
Swift Springs 65mm 7inch 9k
Swift Helper Springs H65-070-008

When I talked to KW they told me that you really should have helper springs on the rear but that added 2 inches of length/height. Without the helper spring I have about a 1 1/2 inch wheel gap and only 3/4 of an inch I can go down on the SPL midlink cup. When you add the suggested helper spring, that adds 2 more inches to the gap. Do I need to go to a 5" or 6" spring? All I am aiming for is to get rid of the wheel gap. A shop did the work and is going to swap out whatever spring I get but they really are not sure what spring length I should go with.