Stacking aluminum lowering block?

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Mojoe9955

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Anyone do it? Does a 1" block actually lower the rear 1"?
 
I would not stack multiple lowering blocks. Get the right size for what you need. I suppose you could weld them together if you stacked a couple smaller ones to get the height you wanted, but I wouldn't run them stacked and not welded together.

As far as how much the block will lower the car, it will lower it the same amount as the height of the block. The block goes between the spring and the axle. So if the block is 1" tall, you will lower exactly 1" because that's how far you raised the axle with respect to the spring.
 
Agree with Blu n Blu. Just get the height of block you want, rather than asking for trouble stacking em, or welding together something you might not want welded later on. I made mine out of 2x2 6061 billet.
And remember, depending on how much drop you want, you may, or probably,, need new longer u-bolts.
 
I wanted to go 1.25 which really isn't avaliable. Speedway has from .25 to 4". I thought of stacking a 1 and .25 and I wouldn't have to get longer u bolts. I measured again and will probably get a 1.5 billet kit from somewhere that includes the U bolts. Mancini?
 
I would only use blocks as the last resort. Always best to lower with the correct springs, or with adjustable height spring perch. Adding blocks to lower, will also increase leverage on the springs which will induce spring coil.
 
I wanted to go 1.25 which really isn't avaliable. Speedway has from .25 to 4". I thought of stacking a 1 and .25 and I wouldn't have to get longer u bolts. I measured again and will probably get a 1.5 billet kit from somewhere that includes the U bolts. Mancini?

These guys?
https://www.speedwaymotors.com/Speedway-Aluminum-Extruded-Leaf-Spring-Lowering-Block,3353.html

If you wanted 1.25" I'd get a 1/2" and a 3/4", since the 1/4" ones don't appear to have a pin. Those two would be held together by the center pins. I'd still probably put a couple of tack welds on them once I had them installed and confirmed it was the height I wanted, but I can weld aluminum so it's not really a big deal for me.

So you already have 1.25" of threads hanging out the bottom of the nuts on your U-bolts?

I would only use blocks as the last resort. Always best to lower with the correct springs, or with adjustable height spring perch. Adding blocks to lower, will also increase leverage on the springs which will induce spring coil.

With 1.25" of block it's not really going to be much of an effect.

Lifted trucks run blocks that are 4" - 6" tall all the time, very common. Heck the old F-250's were called "hi-boys" because they came straight from the factory with 4" lift blocks in the back.


Cut down a 2" block. That's what I usually do on early A-bodies to get 1 1/2".

Why? 1.5" blocks are readily available, just see the speedway link.
 
I wouldn't use aluminum, period. But that's my personal preference.
 
I swapped out the worn out slant 6 springs with heavy duty Mopar 6 leaf springs, not quite Super Stock but they are stiff. And the back of the car was sky high. I also forgot to mention that I already flipped the stock hangers to lower it about an 1" already.
 
These guys?
https://www.speedwaymotors.com/Speedway-Aluminum-Extruded-Leaf-Spring-Lowering-Block,3353.html

If you wanted 1.25" I'd get a 1/2" and a 3/4", since the 1/4" ones don't appear to have a pin. Those two would be held together by the center pins. I'd still probably put a couple of tack welds on them once I had them installed and confirmed it was the height I wanted, but I can weld aluminum so it's not really a big deal for me.

So you already have 1.25" of threads hanging out the bottom of the nuts on your U-bolts?



With 1.25" of block it's not really going to be much of an effect.

Lifted trucks run blocks that are 4" - 6" tall all the time, very common. Heck the old F-250's were called "hi-boys" because they came straight from the factory with 4" lift blocks in the back.




Why? 1.5" blocks are readily available, just see the speedway link.
I use 2" blocks to cut down because they're on the shelf locally.
 
I wouldn't use aluminum, period. But that's my personal preference.

For a short block I really don't see the issue. The force you're worried about is on the U-bolts.

I swapped out the worn out slant 6 springs with heavy duty Mopar 6 leaf springs, not quite Super Stock but they are stiff. And the back of the car was sky high. I also forgot to mention that I already flipped the stock hangers to lower it about an 1" already.

Which 6 leaf springs are you using? The absolute highest spring rate those should be is 130 lb/in, if they were for the 383 cars. The standard XHD's are only 110 lb/in. Neither should really be really stiff or raise the back of the car all that substantially.

I use 2" blocks to cut down because they're on the shelf locally.
Fair enough!
 
I cut many aluminum squared/round tubing and channel's for store fronts and other retail applications, and although I did welding on lots of light gauge steel, I never have welded aluminum.
 
I'll think about it all tonight and get the #s off those springs tomorrow.
 
Are your springs new? Last time I installed new springs it took a little while but they did come down quite a bit.
 
Lowering it with blocks causes spring wrap on acceleration. Also tilt when going into a turn. I have a 4spd Barracuda here right now with steel 1 inch lower blocks . Tires rub in turns and the car handles like ****. Also has wheel hop with sticky tires. Get the correct springs. Springs should run with little arch or you will create leverage on the bushings in turns. Buy a truck.
 
I used 1" steel lowering blocks on my car, but boxed in the perches and welded the blocks 100% all the way around to the perches. I also have -1" split mono leafs with Caltracs on it as well. I am running 30" tall tires and it now sits about stock ride height.
 
For a short block I really don't see the issue. The force you're worried about is on the U-bolts.



Which 6 leaf springs are you using? The absolute highest spring rate those should be is 130 lb/in, if they were for the 383 cars. The standard XHD's are only 110 lb/in. Neither should really be really stiff or raise the back of the car all that substantially.


Fair enough!
I looked at my springs, not sure, but I think they are 2835046 which I'm unable to find anywhere. The closest I can come up with is 2835064 which according to an old for sale post here fit a 69 Dart 340. According to General Spring that spring in a similar configuration 6 leafs with 35" rear and 20" front segment will work on 64 to76 Dart/Valiant and 64 to 69 Barracuda as well as providing 2" of lift. They are used springs that have a decent arch and as I said put the rear super high.

IMG_20240220_095153.jpg
 
I lo
I used 1" steel lowering blocks on my car, but boxed in the perches and welded the blocks 100% all the way around to the perches. I also have -1" split mono leafs with Caltracs on it as well. I am running 30" tall tires and it now sits about stock ride height.
I lowered my car over 6 inches in the rear. 2 inches with sliders. 3 inches with rails and 1 inch with lowering mono leafs. The front 4 inches I used 2 inch lower coil overs and 2 inch drop spindles. Then leveled the car with tires. I refuse to use lowering blocks. It changes the geometry of the spring and their function.

You can easily lower the car 1 inch in the back using sliders on the rear of the springs and lowering hangers on the front.
 
I had 255/60/15 tires on it. This morning I swapped over to some 275/60/15 which are almost an inch taller and I like it a little better. The backspace on the Torque Thrust is only like 3 inches so they stick out a little on early B body 8.75 that is on the car. The 255's were on cop wheels which I think are 4 inch. Maybe the 275's on the cop wheels, get the front end up a bit and call it a day?

17084445957697833041007583915356.jpg
 
However you end up lowering it, be sure to check your pinion angle afterwards.
 
I looked at my springs, not sure, but I think they are 2835046 which I'm unable to find anywhere. The closest I can come up with is 2835064 which according to an old for sale post here fit a 69 Dart 340. According to General Spring that spring in a similar configuration 6 leafs with 35" rear and 20" front segment will work on 64 to76 Dart/Valiant and 64 to 69 Barracuda as well as providing 2" of lift. They are used springs that have a decent arch and as I said put the rear super high.

View attachment 1716209698

Well if they're 2" lift springs that would certainly explain the arch and why the car sits so high in the back. The best way to deal with that would be to have them de-arched

I had 255/60/15 tires on it. This morning I swapped over to some 275/60/15 which are almost an inch taller and I like it a little better. The backspace on the Torque Thrust is only like 3 inches so they stick out a little on early B body 8.75 that is on the car. The 255's were on cop wheels which I think are 4 inch. Maybe the 275's on the cop wheels, get the front end up a bit and call it a day?

View attachment 1716209777

Which B-body rear axle do you have?

Cop wheels are 15x7 with a 4.25" backspace. With any B-body rear that still won't be enough to clear 255's on those rims with you lower the car, let alone 275's.

I have a 68-70 B-body rear axle in my Duster, and even at stock ride height the most that would fit on cop wheels was a 225/60/15, and they were very close to rubbing. The 68-70 B rear is 60 1/8" wide, even if you have the shorter 65-67 rear that's still 59.5" wide, so you'd only gain 5/16" in clearance per side, which probably wouldn't even get you to a 235 unless the quarter lip is well above the tire, like it is now. To clear 275's on a stock height or slightly lowered car you'd need a lot more backspace.
 
I already have questions about the pinion angle, but that's another story. It has a 65/67 B body 8.75 that has the perches moved to 43" on center to fit which checks out but the pinion seems angled up a little excessively.
 
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