My 68 FB convertible, 350 is all stock and original as far as I know. I want to replace the old rear leaf springs. When I went to order the 5 leaf from Classic Industries, they told me it should be a 4 leaf. So what is the proper leaf spring for an original all stock no AC car. Thank you.

5 leaf.

4 leaf are for 400 models. (don't ask)

You may have better luck ordering springs through NPD. That's where I have purchased them for my last 4 '68's.

(National Parts Depot)

I 2nd that

They sell Eaton factory OEM springs. They are the original manufacturers for leaf springs et all for Pontiac.

Thank you. 5 leaf it is, NPD. Any tips on the installation? One of my winter projects.

Buy 6 new cage nuts for the front spring pockets, good chance you'll have to cut yours off as they tend to spin from the backside and you have no access to hold the nuts to prevent it. Also buy new spring pads and new shackle bushings. Those are all pretty much on the mandatory list.

On the "maybe" list depending on condition of your car: new shackle bolts/nuts for rear, front eye bolts/nuts, plus t-bolts and u-bolts/nuts at the axle...those all depend entirely on the condition of yours, how much rust you have, and how cleanly they remove. You might be able to re-use your bolts and hardware if it's not a rusty car.

Here's something that might scare the bejeepers outta ya: My rear spring replacement (in 2002) led me to a full frame rail replacement...which in turn led to a full blown restoration that took me the better part of a decade for multitude of reasons. The car is now finally back on the road...

I do not wish that on you. Mine was indeed a basket case, worse than most. If your car is not rusty, it's just a weekend project.

I see the 5 leaf standard and the 4 leaf HD both have a spring rate of 103. Anyone know if one sits higher than the other?

I think the arch height has more to do with that. The 4 leafs are a bit stiffer for the 400 models. I think you can order stock height, or a bit higher than stock. Remember that stock height gives the cars a lower stance in the rear than many care for. Original cars always were lower in the rear than in the front.

I also have a 68 convertible (sprint 6 ) and my car has original 4 leaf.

I think I will have to "spring" for a pair. My originals altho I had them re-built are sagging about 1/2 on one side. drives me nuts walking up from behind and seeing it.

Wanna hear something disappointing? My pair of brand new replacement/repro springs have a similar sag to one side. Top of right wheel arch to the ground is about 1/2" higher on one side than the other.

Mine (both front coils and rear springs) are from these guys: http://www.johnrspring.com/
I woulda raised some heck about it, except for the fact that I purchased them real cheep back in 2001 and put them on a shelf, and didn't install them until late 2011/early 2012...LOL. Didn't really have the gonads to call and complain 11 years later when I finally got around to the install. Haven't the foggiest where the receipt is anyway, plus the hassle of having to reinstall one or both again? No thanks...

Instead I got the differential to about 1/4" by relocating battery to right rear corner, and making sure to mount my spare tire to right rear corner, and making sure to stuff my toolbox in the right rear corner, etc...

It's good enough to make me happy...we'll see if time settles 'em further...

They still beat the heck outta my originals...a center leaf on one side was cracked clean in half...making a VERY noticeable sag to one side. I'm overall very happy with the stance and handling I ended up with after replacing all 4 corners and redistributing some weight.

But that is one crowded right side of my trunk LOL!! But that's the best spot for traction weight, so all is good!

Went with Eaton on three or four cars now and stance is perfect on all of them. (except the '67 monos sat a little too high for my taste) They settled to a tolerable level after a couple of years. Never had any uneven settling. The '68 4-leafs all sit perfect.

My car has always had a lean to one side. Original springs so I figured it must be them. Just the other day I decided to check it out so I dropped the springs out and swapped them side for side. When I sat them up in the driveway they were exactly the same length and height. Put it all back together and it still leans to the same side. I just made a deal with a guy for a set of Landrum springs. Suppose to be alot stiffer. After my day in the garage I guess I don't really need them afterall but, WTH, it's an upgrade anyway. I'm hanging on to my old ones for now in case the new ones are TOO stiff.

Oh come on Robert, we all know you lean a bit to the left...

It would seem.

So I received my new rear leaf springs for my 68 convert. They were shipped not in any packaging and are a little scratched. I was going to paint them before putting them on. Should I do that or just leave as is? What color were they from the factory? I think these are black now.

Same black as underside of car. (about 60% gloss)

Yes, I would paint them if you want the finish to last a while.

Would you happen to have a paint code number of a particular black that would be correct for paint the leaf springs.

Any paint supply company generally has something called "chassis black". That is a very nice version for underside and engine bay.

I usually use a satin black if I'm at the hardware store. Not glossy but not a flat either.

NPD lists a 5 leaf for 68, 400 convertible, - just FYI, -you sure stock was 4 leaf?

Yes.

x2. the 68 convertible 5 leaf is for the 350. The 400 had the HD springs standard which are the 4 leaf.

Discussed this in another thread. Some docs you can download:

That's funny --- Recursive loop ---

Same thread. Just go to page 1.

Are the rear springs known to be noisey over bumps? My car has a loud metal on metal sound when it hits a bump in the road, sometimes as I back out of the driveway.

It comes from the area of the front of the driver's side spring.... I hope it's not convertible body flex!

No, they should not be noisy. Sounds like you have a problem with the front mount. Those areas are prone to rust. Maybe a bolt is sheared or loose. I'd have it checked out soon.

69 Posi optioned rear ends got three springs.

Has anyone been buying rear leaf springs from ESPO Springs n Things anymore? http://www.springsnthings.com/
There is some reference to them in the FAQ section of this site.

They obtain their American Steel from elsewhere and assemble the springs to factory specs. They are much less expensive than NPD and Eaton at $215/ MATCHED pair for the 4 leaf HD springs. The lower price is scaring me a little. Of course they come painted black like every other spring now, so to make them correct, you need to disassemble them and powder coat or re-paint them if you are going for concourse resto.

Thoughts?