• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Rear Leaf choice - SS or XHD or?

Badvert65, how's the car handle in the corners? any bias to either side?

I'm just going off of what that b-body upgrade book suggests, in running a matching pair for improved 'circle track' work. Happy for it to roll either way.

Hard to answer as it is a street/strip car (no sway bars-front or rear). That being said, if you didn't know the springs were different, you would not be able to tell in daily driving. The extra leaves are there to control axle windup during acceleration. The 'rear' half of the springs are basically the same and this helps the car sit level.
FYI, Mopar designed the SS springs to raise a car by approximately 2 inches. The XHD springs are the factory springs that were on the high horsepower cars. For what you are considering, you should definitely go with the XHD springs. Personally, I don't think you will see much difference if you go with two matching springs over the left/right set. (based on my street driving).
 
I'm just doing front for now with Wilwoods. Keeping the rear drums for now. It should be cool.
 
I just put a set of XHD springs on, they sit level (or at least you don't notice a lean). You can of course go with a balanced set of 2 passenger side ones if you want a little additional stiffness for circle track. I don't like the look of a B body jacked up 2" in the rear with SS springs unless tubbed or purpose built for the straight track... Too much rake also effects cornering in a bad way.
 
FWIW
Here is a photo of my '68 Coronet that I upgraded to Mopar Performance's .920 torsion bars and XHD leafs.
This is a small block car. The upgraded bars and springs improved the ride over the original bars and springs, but the handling didn't improve until I installed front and rear anti-sway bars. I went with Firm Feel's 1 1/8" bar up front and their 3/4" bar in the rear.

006_zpsa2d105c2.gif
 
I have to say that color really compliments the shape of the Coronet.
 
Any car sits a bit crooked when you put the SS springs on but all you have to do is adjust the torsion bars to fix it. I have done it a ton of times and I always adjust the torsion bars and they all sit level when I am done. I put SS springs on my 63 and my buddies 65 you see here. As you can see they look pretty level sitting to me. Ron

100_1795.jpg
 
Thanks guys, Exactly what I was after.

Does anyone sell a two hole leaf spring hanger for the stock length spring? I've only found the SS length one. My bolts are fused in place and I'd like the option to lower the rear if it sits too high.
 
Thanks guys, I've been digging through some older threads as well trying to find extra opinions. I did notice that a lot of people noticed the SS springs raised the rear a fair bit. How much taller then stock will the SS springs be? Or whats the height of the rear with the SS springs? floor to top of wheel arch seams the most appropriate measurement...

I know I can use the higher spring mount on the hanger, but there was a lot of talk about it stuffing the pinion angle - so shimming would be needed. Wheres the best place to get shims etc?

The B-Body upgrades book I have mentions using the same leaf springs on both sides for 'auto cross' etc. Which is why I was going to go that way, looking for all round performance rather then straight line stuff. Has anyone on here done it? Does it lead to noticeable twist in a hard launch?

Thinking that twin passenger XHD's (7 Leafs) or Twin Drivers SS springs (6 Leaf) might be the way to go.

Could I add a Caltrac or 'Assassin' traction devices to either set up later? Found mixed comments when I searched.

Also, thanks to the guys that mentioned custom made ones, but I'm based in Australia. So some where like SUmmit where I can get MP springs for a good price and bundle the postage cost with other products is just more financially sensible. I'd hope that mopar performance springs would be good enough quality any way!

I have a set of SS springs on my 70 Roadrunner that I put on back in 1985. Six leaves on driver's side and 8 leaves on passenger side. The passenger side (with the 8 leaves) sets lower than the driver's side. The SS springs raised the rear bumper of my car about 4 inches (or more) vs. the stock springs. I have the SS style front shackles, so I moved the front leaf spring mounting bolts to the upper holes (lower holes = stock location) and it lowered the car BUT even with 4-degree shims (the max that is recommended) it was not enough to get my pinion angle correct (or even close to correct). My choices were to cut/re-weld the spring perches to correct the pinion angle OR to move the front spring bolts back to the lower/stock SS front spring bracket holes and add 2" lowering blocks (which is what I did & the rear end now looks about stock height, maybe 1" higher). The downside to the 2" lowering blocks is that my "slapper"/bolt-on traction bars wouldn't clear the ground anymore so I had to use an adjustable pinion snubber and everything seems good now.

It's a tough call & I've been thinking about CalTrac's / newer SS springs / XHD springs / two of the same side SS springs / ladder bars / etc.

1. CalTrac - I'm reading they're bumpy and rattle on the street & not that cheap, but I'm leaning that way. It seems like you really need to use the CalTrac mono-leaf springs with the CalTrac bars, so my rearend lean would go away and the car would set even, maybe even hook better at the track.
2. New SS springs - likely will still sag on passenger rear like I have now. It doesn't look that good, but it is how Mopar designed them to launch straight at the track (I do drag race 4-5 times per year). Some people say you can adjust the passenger torsion bar a little higher and sort of hide the passenger rear sag, so I might give that a try first. FYI- my SS springs don't feel all that bumpy
3. XHD Springs - I'm not hearing a lot of good things about their quality, so I probably won't go that way
4. Ladder bars - I just might do this. It's old school and kind of "track only" but that's never stopped me before.
5. Two of the same side SS springs - This seems like the cheapest way to a)get the car to set even and b)get a quality spring and c)not spend a fortune. The problem I have with this is that I do race the car and I'm afraid that it will launch sideways if I don't use a left/right SS spring. This does seem like a good idea for a street-only car.
6. Springs 'n Things / St.Louis Spring / EMCO - all seem like a better option that the XHD springs (better quality) if you want the car to set level, give a pretty smooth feeling ride and you don't drag race.

My two-cents
 
Auto Transport Service
Back
Top