I am doing body work while contemplating what to do suspension-wise. This is very helpful in my decisionmaking process. Thanks!

 

What's wrong with the mono leaf setup

 

I am a strong believer in "if it ain't broke, don't fix it... unless you have an extra large budget, special needs, heavy experience, or just like building more than driving!"

If you have read any of my recent posts, I highly recommend, especially for a first build, building from a plan of what you want the truck to be when it is completed and what is needed to fix a weakness in the suitability for the task, not from what your well meaning but actually clueless friends think is the "kool way" to do it, what is shown in the magazines, or what the aftermarket suppliers want to sell you. For example I'd guess that 50% or more of the IFS swaps were done for the above reasons, NOT because of any significant need, superiority or glaring weakness in the beam axle.
Same goes for mismatching systems: IFS used with straight line racing design rear suspensions such as parallel 4 link or ladder bar for primarily street cruising. If your main purpose is to build a strip terror, then use the previous systems for their launch adjustability, but couple it with a light weight equally adjustable front suspension, such as a tubular beam axle. the front end isn't going to spend much time on the ground and it doesn't matter how well it goes around corners, but you don't want the front end to have a lot of bump steer at extremes of the suspension travel so it doesn't get squirrelly with the weight shifts. If you live in the mountains with a lot of long curvy roads to cruise, then a full matched front and rear IS may be the best choice. If you are building a lawn show ornament, and have the big bucks, then a sophisticated computer controlled air bag system may be the way to go to impress your fellow exhibitors with how much money you spent for that 15.00 trophy. But if your budget doesn't allow for the $$$ control system then buy a trailer and a tow vehicle to haul it around with rather than trying to drive it more than a few miles.

 

I love reading your posts!

 

Short answer: they don't work. GM tried them in the 60's as a cheap rear suspension on the Chevy II and abandoned them after just a couple years. They curl up into an S shape on strong acceleration and deceleration producing serious wheel hop. The heavily tapered ones are an attempt to minimize that characteristic at the expense of the ride. The traditional multileaf spring is a progressive rate design that you can't get with a single piece of metal. Removing every other leaf in the stock stack and putting in HMW plastic slider strips, or replacing with multileaf lowering springs is far better for less or about the same cost. Look at the spring chart in the Mid Fifty catalog for ways to lower and improve the ride. (Note they do sell monos, so they include them in the chart)

 

It's definitely not Gina. I'd recognize her rear end a mile away.

Sorry, got to get my first twelve posts in.
I'll behave now.. for a while, anyway!

 

Since it was funny, you're forgiven! Welcome post away!

 

I did read about removing every other leaf and it sounds like a good idea. I guess the moral of the story is for my level of experience, the four link setup is a waste of money and only for show. I guess I just wanted to get a lower stance and thought the looks of the four link was classy.

 

There are a lot easier and cheaper ways to get a lower stance. Again I refer you to the MF catalog. Parallel leaf rear suspension was the preferred suspension used well into the 70's until cars were downsized and there was less length in the rear for the suspension.
The triangulated 4 link is for more than show, but the complexity vs benefit for local road driving is not justifiable. How many times is it likely someone will crawl under your (lowered) vehicle to admire the suspension and actually understand what they are looking at? Is impressing those few that important?

 

Well gentlemen, I think my mind is made up. Nine inch and stock leaf springs, maybe I will take some out or even put it on top of the axle. Thanks for all the advice. Four links do look sexy though....

 

Springs already go on top the axle. If you mean axle on top the springs, that will make a major drop and require a C notch in the frame for clearance. I'd suggest leaving it under the springs and use leaf removal, lowering springs, reversed eye lowering springs and/or rear hanger relocation first, you can get it plenty low enough that way. Reversing the axle will make it too low unless you also use dropped spindles on the MII IFS then look out for speed bumps and driveway approaches. You can always flip it later. Unless you plan on hauling heavy loads regularly you'll definitely want to at least take out every other leaf on the stock springs. Read the instructions in the Mid Fifty catalog as to which leafs to remove.
Safety notes: Use two LARGE HD C-clamps, one on each side of the center bolt when disassembling the springs. The springs may look harmless enough, but they pack a great deal of stored energy and can break an ankle or worse. Lay the spring on it's side and STAND ON TOP OF IT with both feet to keep them out of harms way as you loosen the bolt down to about 2 threads left. Slowly loosen the clamps back and forth evenly until the bolt is tight again then remove the bolt and finally finish removing the clamps. If you use a wire brush or power sander, make sure it is one that sands in a straight line only (like a belt sander, not an angle grinder or orbital sander) and sand so the scratches are lengthwise to the leaf only, NEVER across!. DO NOT paint the leafs! Round the ends of the leafs with a grinder. If your springs have round depressions in the end of the leafs, use plastic slide disks, otherwise put in plastic slider strips (available from Mid Fifty) between the leafs and reassemble with new shorter center bolts (from guess where?) Replace the eye bushings (easiest way to remove them is burn them out with a propane torch), hanger bushings and hanger bolts.

Just in case you are wondering, the aftermarket rear sway bar is of limited benefit with the parallel leafs.

 

Wow, you are a wealth of knowledge. I did get the mustang2 with the lowered spindles. I just want to take up the space between the top of the tire and the wheel opening. I had a 78 Chevy step side that had 2 broken leaf springs so I took everything out except the main spring and the helper. It lowered it down plenty and never have any problems, but I did have a 250 straight six, so there was no tire spinning for me.

 

And no I don't plan on hauling anything in it

 

The dropped spindles will tuck the tires well up into the fenders, and will make wheel (offset) choice and tire size critical to avoid rubbing when turning. I'd leave final spring selection for much further down the build, until the truck is fully assembled and near drivable.
I've been at this for more than 50 years.

 

I'm using a fairlane front end so inner fenders won't be an issue. 50 years...that's a lot of experience! We appreciate the help on this forum, especially us rookies