I'm building the suspension on my 69 SS 350 Coupe after some of your suggestions (mildly modified). I put in the 6308"s in the front and you suggested 175 lb. spring rate in the rear. What are the stock spring rates (rear) for a 69 Z28 and SS 350. I ask because JC Whitney has Z28 springs for $104 and if they're ]175 lb spring rate, they wouldn't be a bad deal. They also say they have 6 leaf springs???
Thanks,
John

Stock leafs are 125 lbs/inch. Some factory rear springs are as low as 80.
There is a thread on the JCW leaf springs here: http://www.camaros.net/forums/showthread.php?t=122050

I don't know how good they resist wheel hop, the Hotchkis leafs are pretty good, they use a lowest leaf that is very thick and fairly long, it acts like a traction bar but doesn't bind the suspension.
David

Thanks for the reply! That was quite a post. The reason I want to know the spring rate for a Z28 is that on your web site you say the 6308's are 380# spring rate like the Z28. Does that mean a stock Z rear is the 175# rate you recommend? If so, then maybe the JCW Z28 springs are 175# which would save me a lot of $'s as Eaton wants $550 w/ shipping.
David, I am going with your suggestions on 1st gen. suspension as I am pretty ignorant when it comes to designing suspension. I'm going for a mildly modified (though smooth) feel that I can carve some corners while hot rodding.
Thanks,
John

the Z/28 uses a 4 leaf rear spring, it's probably 125 or very close to that. I don't think any Camaro used near a 175 rate. It's important to have a leaf spring that controls axle windup too, so either the Hotchkis long lower leaf, or thicker front half does that. I forget the JCW rate, it might be in the thread I posted. I dont think you can assume it is unless you get the rate from the manufacturer.

I have a 68 Camaro with 6308's and stock leafs. I upgraded the front bar using my old autox front bar from my 67. It's understeering right now and I plan on testing front and rear bars on it to get the roll under control. The tires are nothing special, 245 60 15's, sort of an average street car, which is what we use the car for. I want to set it up as a nice streetable package. For the power level and ride height and tires this car uses, the springs don't have to be super stiff and the tires are not going to generate 1 g cornering so why have the suspension rock solid? it would be a skate board with a full-on Hotchkis setup.
I'll keep you posted on it when done.

I have eaton replacement 4 leafs in the back of my z28 and 6308s up front. It rides nice but sits low in the back with anything close to 3/4s of a tank of gas. It also bottoms out pretty easily. I wish i had gone with stiffer springs.

I guess I'll spend the big bucks and go for the Eatons.
Thanks,
John

Eaton makes a replacement leaf and a HD leaf, but the HD leaf is not all that good for wheel hop control I hear.

Fwiw, years ago, GM Canada Tech told me that my '67's F-41 mono's were 137 pounds.

pdq67

Paul,
Yes, I always thought the monos were all below 100 lbs, but the F-41 monos were as stiff as any multi leaf.
David

Is eatons heavy duty replacement ther 175 lb version?

I now have JCW's 3-leaf mono replacements under my car that I tore apart and added the second and third leaf's from my old '68 'Bird, five leaf multi's after I broke a mono!

My car now sit's high, just like it did w/ my old coil-over, overload shock springs that I set at like 4"+ taller which was great back then for my old L-60/14's that measure a modern 298-53/14 on a 9" wide rim!! Suckers are still mounted and up on the shelf out in my garage!

pdq67

PS., my old L-60's measure an 11.5" section width and are 26.5" tall! Big Mutha's they are!!!!

Obviously you like the Hotchkis setup. On my 69, I've got a set of 255/50/17's on the rear, and 245/45/17's on the front. The springs are stock, and the stance looks good probably because they've settled an inch or two from new. I like to switch back to the stock rallies occasionally. I want to be sure if I go with the Hotchkis kit. The car doesn't sit wrong with the taller rallies on it.

I like the pro touring look, but I also like the old school stance. I don't really drag or road race, but I want it to handle without the sway and rubbing it's got now. Along with the right ride height.

I guess I'm just looking for a little nudge to go ahead and go with the Hotchkis setup. I just haven't met anyone at any car shows or rod runs in my area that already have it, to talk to first hand.

68 Z28 rear "BR" springs have a 135 lb rate, and a 690 lb load. Thats as close as I can get to a 69 Z28 rate since GM went to a computerized system in 69 and no longer found it necessary to post the rates and loads of the springs in the cars anymore.

Like my stock F-41 mono's.

Guys don't want to hear this, BUT if I was to do this over, I would install roundy-round adjustable front cans and use any one of a bunch of cheap short coils in front and set my ride height anyway I wanted it!

As for the back, mono's and slappers and cheap shock coil-overs that I can adjust!

Thhis is about the lightest, cheapest and the BEST rearend set-up I can come up w/, me and my "poor-man's" way's!!

And this is good to way deep into the 10's!! And also will do a slalom course too if you remove the slapper snubbers!

pdq67