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Old 10-01-2007, 12:03:47 AM   #1
Tphil413
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Lowering Blocks?

Wondering if any of you are running lowering blocks in the rear leafs? I am trying to lower my back end about 1", but can't seem to find any lowering blocks made for a '71 Camaro. If you are running them currently, can you suggest a brand or even better a part number?
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Old 10-01-2007, 01:13:36 AM   #2
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I wouldn't suggest using lowering blocks. They aren't the best thing for the suspension geometry.
Get new springs that lower the rear end
OR if you don't have the cash for that take, the springs and get them re-arched.
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Old 10-01-2007, 08:37:46 AM   #3
onovakind67
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You can buy lowering blocks at most auto parts stores or places like Summit and Jegs. It's an easy installation, and 1" of block will have little effect on the function of the rear suspension. Here's what AFCO racing has to say in their tech section:

LOWERING BLOCKS
Lowering blocks are generally used to change the ride height of the chassis. Lowering blocks can also be used to adjust wedge when multi-leafs are used. The addition of lowering blocks can cause less tightę roll steer which will help the chassis to turn. If lowering blocks drop either or both spring eye positions relative to the axle then the rear roll center height will be lowered and chassis roll, along with rear side bite, will increase.

Too much lowering block* can cause the forward thrust of the rear axle to prevent the leafs (or torque arm) from wrapping up and absorbing engine torque. Consequently, forward bite is diminished. A symptom of this problem shows up on torque arm equipped cars as very little 5th coil/shock movement.
*The distance between the bottom of the axle tube and the top of the leaf should not exceed 4 1/2". What to look for in a quality leaf spring: 1. Smooth, continuous and consistent arch 2. No lengthwise twist 3. High strength steel 4. Heat treated 5. Tension side of leaf shot-peened for increased durability (produces a satin smooth finish) 6. Rubbing blocks between secondary leafs 7. Secondary leafs taper cut at ends. 8. Proper eye alignment (front and rear eyes should be parallel in all directions).



http://www.afcoracing.com/tech_pages/leaf.shtml
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Old 10-01-2007, 08:52:02 AM   #4
John Wright
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Also...using a 1" tapered block will help keep your driveline angles in check, and you could add the tapered shims if necessary. I wouldn't go overboard with the lowering blocks though...but IMHO the 1" block will be fine.
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Old 10-01-2007, 10:28:39 AM   #5
67lemanster
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Quote:
Originally Posted by John Wright
Also...using a 1" tapered block will help keep your driveline angles in check, and you could add the tapered shims if necessary. I wouldn't go overboard with the lowering blocks though...but IMHO the 1" block will be fine.
i agree 1" and less is fine. i wouldnt go any more than that though.
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Old 10-01-2007, 04:39:14 PM   #6
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Thanks for all your responses. I have run them successfully in the past on my '70 RS but was having no luck finding one's designed for my application. Everything out there seems to be for lower trucks. Was hoping one of you could help me get a line on a brand or online store that might sell ones that fit a 2nd gen successfully.
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Old 10-01-2007, 04:43:20 PM   #7
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I'm asking because I didn't realize there was a difference....why can't you run the same 1" block as say a S-10? I think the spring pads on the axle are the same...aren't they?
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Old 10-01-2007, 04:45:00 PM   #8
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Speedway has them in all sorts of sizes.

http://www.speedwaymotors.com/p/3353...ering%20blocks
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Old 10-02-2007, 03:41:25 PM   #9
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what's the cost to de-arch leaf springs, as opposed to lowering blocks?
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Old 10-02-2007, 04:20:17 PM   #10
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Quote:
Originally Posted by protour73
what's the cost to de-arch leaf springs, as opposed to lowering blocks?

If you use a torch... the cost is minimal.
(I'm kidding. )

Removing the springs, paying someone to disassemble, de-arch and reassemble is going to cost you far more time and money than a $10 set of blocks. You will need longer "U" bolts so add that to the cost of lowering blocks.

I think you will be fine with 1" blocks on our 2nd gens.
(Or throw a full-size spare in the trunk and run with a full tank of gas as much as possible. )
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Old 10-02-2007, 04:58:02 PM   #11
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And when you order the longer U-bolts, make sure you order them in the correct quantity. They are supplied in pairs!

I used this method to lower my '68 SS and if I remember correctly, the 8-inch U-bolts were the correct length. You need four. Car sits lower and rides just fine for a stock, touring car.

Summit, Jegs, et al, has these blocks in stock.

Cheers,
Mary Pozzi
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Old 10-02-2007, 05:05:17 PM   #12
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Good Point, Mary!

The stock "T" bolts won't work with blocks so you need to replace two of them on each side with another "U" bolt.
(You may have to move the clip holding the brake line to the axle tube too.)
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Old 10-02-2007, 06:23:30 PM   #13
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It's also a pretty easy job and you'll need tools (natch . . . preferably with air), couple of jack stands for the body, and a hydraulic jack to support and chase the rear axle/differential all over the shop floor after it's loose from the chassis. Watch out when you raise and lower the rear axle assembly and you may have to disconnect the brake line flex hose above the differential first. If so, add a flare nut wrench and brake hydraulic fluid to your "tool" list.

Watch out when you reposition the metal brake lines that travel along the rear axle tubes to fit the new U-bolts as the lines will easily fail. They're as old as the car and have many miles of vibration and intermittent contact with anything they're positioned next to. When I dropped the SS, I discovered the brake line seeping after I installed one of the U-bolts. It was worn through the corrugation spring that protects the line and then got through to the line itself. I guess some things don't last 40 years or so . . . Steve's Camaro Parts in San Bruno, CA had replacement lines so I replaced both sides. You don't want to take chances on anything with brakes or steering.

You can also elect to replace the leaf support pads at this time. I used polyurethane pads (black ones) and they work fine. Or you can leave them out . . . personal preference. For something stock, I'd replace them.

Cheers,
Mary Pozzi
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first watch http://www.youtube.com/watch?v=JkmLy99TyXU

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Old 10-03-2007, 11:40:01 AM   #14
nx74ls6
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Quote:
Originally Posted by onovakind67
You can buy lowering blocks at most auto parts stores or places like Summit and Jegs. It's an easy installation, and 1" of block will have little effect on the function of the rear suspension. Here's what AFCO racing has to say in their tech section:

LOWERING BLOCKS
Lowering blocks are generally used to change the ride height of the chassis. Lowering blocks can also be used to adjust wedge when multi-leafs are used. The addition of lowering blocks can cause less tightę roll steer which will help the chassis to turn. If lowering blocks drop either or both spring eye positions relative to the axle then the rear roll center height will be lowered and chassis roll, along with rear side bite, will increase.

Too much lowering block* can cause the forward thrust of the rear axle to prevent the leafs (or torque arm) from wrapping up and absorbing engine torque. Consequently, forward bite is diminished. A symptom of this problem shows up on torque arm equipped cars as very little 5th coil/shock movement.
*The distance between the bottom of the axle tube and the top of the leaf should not exceed 4 1/2". What to look for in a quality leaf spring: 1. Smooth, continuous and consistent arch 2. No lengthwise twist 3. High strength steel 4. Heat treated 5. Tension side of leaf shot-peened for increased durability (produces a satin smooth finish) 6. Rubbing blocks between secondary leafs 7. Secondary leafs taper cut at ends. 8. Proper eye alignment (front and rear eyes should be parallel in all directions).



http://www.afcoracing.com/tech_pages/leaf.shtml

I just got on the phone with Summit to order the lowering blocks and they said that THEY CAN'T BE USED ON A 2 ND GEN. He said they are for truck appl. - and for lowering he recommended the Hotchkiss spring ($380) lowering....I' d like to use the blocks, but I'm confused. Any help? Thanks.
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Old 10-03-2007, 11:49:27 AM   #15
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Try Speedway...in link above.
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