Strut size question

[Stinkbug]

Hey brains trust. 
im looking at putting coilovers in front of my 260z. 
I have 55mm struts at the moment but have the opportunity to buy a pair of 51mm complete with stub axle and caliper mounts already attached. 
will they bolt straight in? Or is there a difference between the larger strut?

thanks. 

[C.A.R.]

Stick with your 55mm struts.

[gilltech]

I second CAR's reply above.

FWIW, I replaced the 51mm struts in my early '74 260Z 2-seat with the later 55mm struts; they are shorter in overall height plus have a different spring length. They nicely lowered the front down where I like it without any fuss with changing springs. I wouldn't want to go the opposite way.

But whatever you decide to do, compare all dimensions first to ensure you will get the ride height you want.

Edited December 12, 2023 by gilltech

[Stinkbug]

I have a late 75 2 seater. 
it seems I have kdfl-08 springs in the front. They are the 240z part number. 
I’m trying to figure out if the kdfl-04 (260z) part number are taller and will give me the extra inch or so I need to raise the front. Confusing business this……

[gilltech]

Springs can be a messy area. To raise the ride height you will need either longer springs, or stiffer springs, or a combination of both. Of course both are subject to the length of the strut and the strut insert in the first place which affect the amount the springs are pre-loaded when installed.

I have tried the KDFL-04 springs but found them too short to be captured by the top and bottom retainers, and that's clearly unsafe - in order to use them I would have to install shorter strut inserts. They were also very stiff - with the car on the ground and trying to bounce it up and down they barely moved. So I gave up on them and had my factory springs reset to the length I wanted instead.

If it were me, I'd get hold of a set of factory 260Z springs to put the car back to factory (approx - they will have sagged a little over time anyway) and see how they go for ride height before experimenting with other struts and springs.

My 2c worth anyway.

[Stinkbug]

Thanks mate.