I am redoing the suspension on a 71 and I am keeping the original springs. The car has 85k original miles and the springs aren't even rusty. When i took them off I examined them for differences but couldn't see any difference from front to back or side to side. If anything, the passenger front looked maybe an 1/2" longer . Were the spring rates and heights all the same? Or should I be looking for a heavier coil spring on the rear springs? I have searched but haven't found much on the original springs.

If you don't have a mic to check spring wire size use a cresent.

FRONT SPRINGS 71 240

Wire Size----------.425

Spring Length------15 1/4" Right side

Spring Length------14 3/4" Left side

REAR SPRINGS 71 240

Wire Size----------.452

Spring Length------15" Both sides the same

And as you may have figured out from Dave's specs, the spring rates are definitely different front to rear.

And as you may have figured out from Dave's specs, the spring rates are definitely different front to rear.

I did not include the spring rates, but they are 83 pound front and 103 pound rear.

A fairly accurate way to check/compare spring rates is to use a drill press and a bathrooom scale. set the spring on the scale and put the spring holder on (easier for the press to put even pressure) and put pressure till you hit 50lbs on your scale then set the inch dial for reference and from the 50lbs reference point apply one dial inch worth of pressure and what your scale reads will be your spring rate.

Springs also sag over time. There is ample justification to replace them even if they're not rusty.

they're still 30+ years old.

try the eibach progressives. they're relatively cheap. bought them on ebay but you can get them at summit racing and other online sites, shop around.

Thanks for the replies gentlemen. I posted and had to run off to work again so I didn't reply right away,sorry. I definetly noticed the taller front passenger spring and I do have mic so I will check to make sure I get them on correctly. Even with worn shocks (I believe original muhollands) the car didn't look like it sagged at all. With 85k miles , I'm going to stay with the originals to save some bucks and after I get it back together I will reassess the situation. If the springs look or feel bad I will replace then.

thanks again

in case you replace your springs with after market springs, my experience with ST springs was that the rear springs are longer and have about 1 tyrn more than the front.

so be carefull.

cheers.

in case you replace your springs with after market springs, my experience with ST springs was that the rear springs are longer and have about 1 tyrn more than the front.

so be carefull.

cheers.

That may not apply to 240Z springs, they are different that 280Z.

ops! didn't know that..

sorry..

I was talking about a 280Z..:tapemouth

thanks for the info Arne.

Steve, if you are staying with those Mulhollands, you'll probably be fine with the stock springs. However, I found that KYB GR-2s raised my red car's ride height by over 1/2" once they broke in. That's with unsagged stock springs with 62,000 miles. I recently put my stock springs into storage. Since I wasn't interested in lowering the car at all, I cut down and used a set of the reproduction Nissan Euro Stage 1 springs. Had to cut 2 coils off each front spring and 1 3/4 coils off the rears, but now the car sits at the stock ride height, and the ride is pretty much unchanged.

Madkaw, I don't know if you've already moved on with this job, but you should know that not only are the front and rear springs different, but the left front and right front springs are different. I don't know if they still have any, but if you want to remain stock Courtesy Nissan had sets of Original Spec springs that we had made by a spring company. They also produced some Euro Spec I springs for Courtesy to sell. I have the Original Specs with KYB GR-2 struts and it is plenty firm for me as a street car. It takes quite a bit of effort to even push a corner of the car down.