47-55.1 51 chevy 3100 truck rear lowering

[hopalong]

Have a 51 and like to get some input on how to replace the original leaf spring brackets with without going aftermarket to lower the truck by raising the brackets up. I see some aftermarkets have kits that include the mono springs. Really don't want to do the mono thing or use lowering blocks or 4 link. Looking for modifications for making leaf spring brackets. Purpose is to get the rear lower about 3 - 4". I have a Mustang II suspension up front at about 3" below stock height. The original rear was removed and replace with a 8.5 gm posi rear
Thanks

[mongocanfly]

do those spring brackets not fasten to side and bottom of frame rail?..and spring under frame rail?...if your soa ,can you swap to sua?

[_Ogre]

Originally Posted by hopalong

I have a Mustang II suspension up front at about 3" below stock height.

check with others that have mustII on a 51 to make sure of that 3"
i know the 55-59 mustII kits go 6" or 7" down from stock

an easy way to lower the back on stock everything is to Z the frame

[mr48chev]

One issue is that when you pull the stock rear out and use thin spring pads with the new axle it actually raises the rear of the truck an inch or so.
If this works it is a photo of my truck just after I chopped it the first time when it still had the I beam under the front and the stock leaf springs under the rear with a 68 Camaro rear axle. N-50 14 rear tires. That was about 1979. No lift in the rear as that was how it sat.



You could do a bunch of fabbing to get the springs closer to the frame rails but you might want to look under a late 80's early 90's Mopar mini van at the wrecking yard. The whole leaf spring assembly with brackets unbolts from the mini van and with a few new holes can be bolted to your frame. I think there is a thread somewhere on here about it. depending on short wheel base or long wheelbase the rear springs are different lengths. I've got an 88 Dodge mini ram panel van that is going to loose it's rear springs when the time comes and I don't need it for a 30.00 storage shed anymore.

[hopalong]

Originally Posted by mongocanfly

do those spring brackets not fasten to side and bottom of frame rail?..and spring under frame rail?...if your soa ,can you swap to sua?

what do mean in "soa and sua ? thanks

[hopalong]

Originally Posted by _Ogre

check with others that have mustII on a 51 to make sure of that 3"
i know the 55-59 mustII kits go 6" or 7" down from stock

an easy way to lower the back on stock everything is to Z the frame

with a 2" drop spindle I can go about 6" but thats not my issue, its the height of the rear. The distance from the rear housing hitting the bottom of the frame is not a problem on the 47-54....would be on a 55
Thanks

[mongocanfly]

soa=spring over axlea
sua=spring under axle

[hopalong]

That was simple explanation ....thanks, yes sua .... already...want to elevate the hangers up ...may be mounting new ones on inboard or outboard side of frame...or shorten hanger shackles. I'm sure one has done this...looking for proven ideas to lower the rear height

[hopalong]

Originally Posted by mongocanfly

soa=spring over axlea
sua=spring under axle

The rear leaf springs are the original 6 leaf that were common for the 1/2 ton truck. 1 3/4" w
After checking the rear leaf front fixed leaf spring bucket measures 5" from the bottom of the frame rail mounting to the top of the spring flat leaf at the support bucket. The original front leaf "rear" fixed spring support measures 2" from the bottom of the frame to the top flat leaf. So this would give me a drop there of 3" +- by using the rear front spring bucket mount.

The rear leaf support shackle could give me 1 1/2" drop if I move the bushing/sleeve up in shackle being careful not to affect the swing of the shackle from the rear end/axle when moving up/down.

All of these spring mounts are L type brackets meaning they are riveted to both the side and under the frame.

Thanks all for the info and I'll see what I have by moving the bucket and modding the shackle. Hopefully this wont throw the center off although it is off due to the seller I got if from. I can resolve the centering by drilling the axle perch if needed to move the axle where it should be.

[hopalong]

Well the switch of hangers only gave a 1 3/4 drop.

I have a 425 hp 67 Chevy II with traction bar set up that uses mono springs and I have 2 extra sets in the garage. I'm looking at using these 62- 67 mono springs with Mopar hangers for the truck. Early Camaros used the same type springs design. The Mopar (Chrysler) mono springs has a better front hanger mount than the Chevy II's and mounted on a non subframe chassis. Going to mock up a combo bolt / weld-in front and rear hangers under the rear frame with slight offset. This should give a nice drop with a decent ride without a cheesy flimsy bumpy ride. These mono springs has the same arch as the 52 truck but less load carrying capacity. Some nice shocks would help handle the ride. This truck resto is for street and cruising opposed to hauling heavy loads that the 6 leaf were designed for.

Anyone done the Chevy II or Mopar mono spring install on these 1/2 ton 47 - 54 trucks? Note these are not the split mono springs.

Thanks

similar install article https://www.hotrod.com/articles/1949...3-chevy-truck/

[Marty68]

As I was under mine fixing the Ray charles welded exhaust. I looked at the way these springs are mounted. It seems that with some fab work a guy could make shorter mounts. Not sure if it would be worth it.
I like the idea of new/NEWER springs hangars etc.
As I move along this is something I will address. Open drive and trans swap next week. Then next fall MII. then see how rear sits.

[hopalong]

Well I now am looking at using hd jeep hangers that would put the hangers under the frame and higher up than the truck is now and use 2.5 springs. I see were s10 rear leaf springs are slightly longer but have almost the same weight and load specs that the 1/2 ton truck has. The TCI kit with the lowering springs are about 47 1/4" eye to eye which is shorter than the 51 1/4" truck springs. Main thing is to get a leaf spring where the leaf centering pin is the same measure on the front dimension to the eye as the trucks spring is so as the rear axle housing/perch center mounts over the pin to center the wheel.

I don't care for the trucks oem springs mounting system the way the spring eye attaches inside of the hanger bushing technique. And the springs small 1.5 width.

Could also mount the hangers on the up on the outside of the frame to drop it also. Giving that a thought. So still at the drawing board

BTW the MII bolt on crossovers is a great way to install the MII system. You can find these cross ver kits at Classic industries, Speedway and others. Speedway has good instructions to install it all as well as pictures and tech support. Tack-weld the crossover after finish install if desired