Swapping 260Z spindle for 240Z spindle??? Help

[Zs-ondabrain]

So as most of you know, I'm rebuilding the 260Z this winter but I think I ran into a snag. As the picture below shows, the 240Z front left spindle/strut assemble is 3/16" shorter than the 260Z assembly (2/74) And the 260Z's spring perch is 1" lower than the 240Z's.

So my question is........ If I use the 240Z spindles/strut assemblies and 240Z Eibach PR springs and KYB struts like I would on a 240Z, would there be any ride height differences or unforeseen issues??

From what I can tell, and off the top of my head, The 260Z springs and struts are a slight bit longer, because the spring perch is lower on the strut tube and the tube is 3/16" taller. But it seems like everything else is identical (torsion bar, steering knuckle and control arm)

So what did the change in tube length and lower perch do for the 260Z versus the 240Z???

Thanks for the facts and not overloading the thread with opinions (hint hint)

Dave.

[Zs-ondabrain]

So nobody's ever dealt with this or come across this type of swap?

[Walter Moore]

1 inch lower ride height? (Only if the springs are the same...)

Did the 260 get longer springs? Isn't it a slightly heaver car?

[John Coffey]

Your car is a later 260Z and has the 280Z dimensioned strut tubes front and rear. You need to use 280Z specific components because of these dimensional differences and because the rear strut tower sheet metal in the back of your car is higher in the body then on a 240Z. Your car is essentially a 280Z without the 2.8L engine.

Using 240Z springs on a 280Z chassis makes the rear of the car ride about 1 to 1.5" below level. You can do it, but you'll need to assemble and install the suspension, drive it around for a day, determine how much to cut in front, disassemble, cut, and reassemble.

[Zs-ondabrain]

It's NOT a later 260Z. It's a 2/74' and that's why I'm confused. I guess I'll just reuse the 260Z equipment (struts and springs) But another question would be..........

Is the typical early 280Z front strut assembly longer than the 3/8" that the 260Z seems to be over the 240Z? If that confused you, here's what I'm asking......

240Z front strut assembly is 15 7/8" (8/70')

260Z front strut assembly is 16 1/4" (2/74')

280Z front strut assembly is ?? ???" (_/75') ?????

If I order 260/280Z Eibach Progressive rate lowering springs, and KYB strts, would this be the correct application for my 2/74? Knowing that the 260Z front assembly is only 3/8" longer and the perch is only 1" lower??

I really appreciate any help or opinions that will get me on track. I'm starting to hate this 260Z crap.

Dave.

[John Coffey]

Measure the OD of your strut tube. Typical 240Z strut tubes are 2.010" and typical 280Z strut tubes are 2.150". I can't compare your strut tube measurements with mine because I don't where on the strut you're measuring. I measure the length of the inside of the strut tube and here are the numbers I have:

240Z Front: 15.125"

240Z Rear: 16.750"

280Z Front: 14.750"

280Z Rear: 18"

For the work I do I've never measured where the spring perch is on the strut tube because I'm always cutting them off.

[jmortensen]

One more option: cut the spring perch off and weld it back on higher. Not hard to do...

[Zs-ondabrain]

I measued my 240Z inner tube and it's (with a 1" wide tape measurer) 15.0625"?? or 15-1/16"

The 260Z tube measured at 15.1875" or 15-3/16th

the OD of both tubes is 2"

the ID of the 240Z tube is a smidge over 1 3/4"

the ID of the 260Z tube is a smidge under 1 3/4" and seems to have a thicker inner wall, hense the smidge under term.

The 260Z strut cap screws onto the 240Z tube beautifully.

I'm just gonna reuse the 260Z tubes on the 260Z. I asked the original question because I already had a beautiful set of 240Z tubes ready to go, and I know 240Z's.

So my next question is obviously this...... Part number of the correct KYB struts and Eibach Pro Rate springs for my early 260Z with the measurements above. Thanks for all your inputs, Next Z after this one WILL BE A 240Z. No more 260/280Z crap to worry about from me.

I found this today when I tore into the 260Z front struts. Please tell me that the KYB's are self contained units that I don't have to fill with oil and assemble one peice at a time. What a fricken mess.

Thanks again guys, The second picture is me prepping the control arms for the Urethane bushings. The finish will be hi gloss POR-15.

Dave.

Edited October 28, 2008 by Zs-ondabrain

[Arne]

Yes Dave, KYBs are sealed cartridges.

[Zs-ondabrain]

Again,

My next question is obviously this...... Part number of the correct KYB struts and Eibach Pro Rate springs for my early 260Z with the measurements above. Thanks for all your inputs, Next Z after this one WILL BE A 240Z. No more 260/280Z crap to worry about from me.