Ok so Ive been cuting and welding to figure out the best way for me to do this but i figured maybe I should just stop and ask the experts. Its a 29 model a frame that was totaly stock, I cut the rear and Z'd it about 5 inches with waterjet parts. I boxed the frame as well. I have a 39 rear end with spring behind I would like to use. I have both the stock model a spring as well at the 39 spring. What makes the most sense? I was thinking of trying to run the model a spring with a few leafs out spring behind on the 39 banjo. then bolt it to a the model a cross member that will be moved back from the zed section to keep wheel placement. Does this make sense or would I be beter off running the 39 spring with leafs removes on a custom cross membermoved back?
This frame is not z'd but, BULL built something like yor thinking. http://www.jalopyjournal.com/forum/showthread.php?t=371150
Absolutely! Do the Model "A" spring behind and some day you can do a quick change, 'cause some day soon, you'll want one!
Model A spring will work fine and of course allow future QC. Many would say thit it is cool looking if it's going to be visible. I suspect but can't prove that a '39 spring will work a little more smoothly than an A because it lacks the extra reverse curves, but of course no quickchange for you with the late spring. Shackles...a reasonably good rule of thumb is that if they hang at about 45 degrees when installed and loaded, suspension will work fine laterally. If they hang more vertically suspension will have sway and a panhard bar will be needed. It is somewhat difficult to be sure how things are going to hang before car is complete and on its wheels, so keep a contingency plan... Remember that the late spring mounts on axle will add more drop into what you have with the Z.
Hey that great I ordered some new longerones as I remeber the a spring is a bit shorter anyways so will giv that a try and figure out where to go from there. Cheers Mike
The spring will 'grow' a little when you leave out the odd leaf here and there, so it'll be longer than you might think.
Also with a spring behind if it turns out to not be low enough it can be lowered by using longer shackles. I like a spring behind setup.
Be careful you have enough clearance over the axle. My brother did the frame lengthening/Z-ing and spring behind on his A, but discovered if the spring is de-arched much the axle gets close to the rails. When Ford did the spring behind from 32-48, the rails had more arch over the axle area.
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