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does anyone use a rear leaf spring setup from mid 70's car/truck on their early 30's late 20's hotrods? im new to hotrodding and i was looking around for some ideas, and i couldn't find any info on the subject, all i found was that some of you guys would run just a single leaf spring in the rear, which would be mounted sideways..but i didn't find much info about that either. any info would help. thx guys/girls.
 

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Suspension setups

Fellows run just about any kind of suspension setup you can imagine on those things..What ever the builder/owner thinks will work and/or look neat..

We used the cross leaf because Henry built them that way..ans the croos leaf gives a neat trim look..

Do what ever works for you..:D
 

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There might be a problem or two. I just pulled the rear leaves off an 81 F-150 and did a little reading up on them. There are three potential problems that I see in converting it to a cross leaf.

1) The perchs on late model trucks are not always centered. In other words the distance from the perch to the rear eye is longer than the distance from the perch to the front eye. This means the centering hole (which lines up the leafs in the "stack") will not end up in the center of your cross leaf setup and therefore the "stack" (how the leaves are set on top of one another) will not end up in the center of you cross member. And when you start moving the upper leaves left or right you quickly discover problem number 2.

2) The two ends of the leaves are pre bent in non- uniform bows. The bow from the perch to the rear eye is different than the bow from the perch to the front eye. I quickly tested this out with the leaves from my 81 by taking the longest leaf from the left side and trying to match it up with the longest leaf from the right side but reversing one of the leaves end for end. Sure enough, bows in the leaves do not match up. This might cause you a problem in trying to put it on a cross leaf setup. The left side will be bowed differently than the right. This is assuming you first figure out how to solve the centering problem in #1.

3) And finally, on some late model trucks the "eye"s are different on each end. I'm not sure why this or if it is true on all makes and models, but the rear eye on my 81 springs are curved in a larger diameter than the front eye (not just a mistake, its this way on both sides)

All in all, I think this conversion will cause you some problems. However, there might be a couple of solutions. What I'm doing is cutting the leaves in half and making quarter elliptical springs out of them and mounting them fore to aft parallel with the frame. But I also gave some strong consideration to cutting them in half and mounting them in the traditional cross-leaf configuration. By cutting two sets of springs in half and then just using all lefts or all rights you can eliminate all the problems of the mismatched ends and mismatched bows. You would have to figure out a little different mounting scheme then the normal setup but I think it is doable.

Dewey
 

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If you are determined to do this (and I am the #1 proponent of DIY and try different stuff), you can avoid the real problems that cboy mentioned with junk yard springs by having a new custom one made. All reasonably large cities have a at least one spring shop that specializes in leaf spring work, mainly for big rigs. They can roll you any size or shape spring you want. They can also recondition old springs and even make replacements for broken or severely worn ones. And they can reverse the eyes on stock springs to lower a car. Check your yellow pages.
 

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Modela,

Not to quarrel with Willy's helpful info, but you might want to check with your local spring shop on the cost of doing those mods before you go too far down that line. I have no idea what the going rates are for doing such things but I can't imagine it is cheap. Might turn out that one of the after market chassis suppliers for A's could supply you a brand new front spring for about the same total cost as having a used one rebuilt.

One thing I also discovered about old leaf springs is...they ARE old leaf springs. And they do succumb to years of doing their job. When I took the spring sets from my 81 apart I discovered one of the leaves was split right in two. So just be aware. They do bust from time to time when they get old.
 

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cboy said:
Modela,

Not to quarrel with Willy's helpful info, but you might want to check with your local spring shop on the cost of doing those mods before you go too far down that line. I have no idea what the going rates are for doing such things but I can't imagine it is cheap. Might turn out that one of the after market chassis suppliers for A's could supply you a brand new front spring for about the same total cost as having a used one rebuilt.

One thing I also discovered about old leaf springs is...they ARE old leaf springs. And they do succumb to years of doing their job. When I took the spring sets from my 81 apart I discovered one of the leaves was split right in two. So just be aware. They do bust from time to time when they get old.
It isn't really that bad. Over the years I have had eyes reversed on a few springs, several sets of springs re-arched, several replacement leaves made, etc. A lot cheaper than buying the slick after-market custom springs.
 
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