Lowering blocks with 15" wheels?

[loridr]

Still thinking about what to do with my rear suspension. I'm satisfied with my 4/5 drop.

Current setup is 5" rear springs without relocating shocks or doing a notch and I’m running the stock panhard bar.

Can I run 2" lowering blocks with 15" wheels?

If so, and I switch to 3" springs, that setup would eliminate any need for a notch, I could use the stock panhard bar and I wouldn't really need to relocate the shocks either, correct?

[Mike J]

well, i'm running 2" blocks AND 5" springs with a 15" wheel, so yeah it's definitely doable, i'm also running c-notch, adj. panhard bar and relocated drop shocks, so can't help you with that part of the equation...

[loridr]

Thanks Mike.

I thought that I'd seen in a thread where you couldn't, and the Porterbuilt trailing arm literature makes a point of saying that you can run their lowered arms with 15" wheels (they are a 3" drop though, not 2“).

So that I'm clear on my understanding of the implications of blocks: they essentially push the trailing arms down towards the ground and decrease the clearance between the trailing arm (actually the bottom of the U-bots) and the ground, correct?

[SCOTI]

Originally Posted by loridr

Still thinking about what to do with my rear suspension. I'm satisfied with my 4/5 drop.

Current setup is 5" rear springs without relocating shocks or doing a notch and I’m running the stock panhard bar.

Can I run 2" lowering blocks with 15" wheels?

If so, and I switch to 3" springs, that setup would eliminate any need for a notch, I could use the stock panhard bar and I wouldn't really need to relocate the shocks either, correct?

2" blocks w/a 15" wheel will work but there will be scrub line issues (the bolts will dig into the ground) if you have a flat @ speed. 1.5" blocks won't contact the ground w/a flat unless the rubber comes off the wheel.

5" rear drop is 5" drop regardless of how you arrive there. You're correct & don't need the c-notch unless you put some serious weight in the bed.

5" drop w/springs only definitely needs shock relocators (or shorter shocks) & an adjustable (or modified) Panhard bar to properly center the rear-end. The Panhard bar will be @ an angle that is compromised. It will work but it won't be optimum & will make the truck feel squirrely when turning/cornering on uneven surfaces. The better solution is a Super (long) Track bar (Panhard bar) from Porterbuilt, ECE, or CPP.

[loridr]

Scoti,

Do you see any advantage at all to going from the 5" springs to blocks plus longer springs? Or am I just back where I started? Wouldn't I at least get more spring and shock travel or am I missing something in my thinking?

With 3" springs and blocks would I still need to relocate the shocks? How about 1.5" blocks and 4" springs?

[SCOTI]

Originally Posted by loridr

Scoti,

Do you see any advantage at all to going from the 5" springs to blocks plus longer springs? Or am I just back where I started? Wouldn't I at least get more spring and shock travel or am I missing something in my thinking?

With 3" springs and blocks would I still need to relocate the shocks? How about 1.5" blocks and 4" springs?

I feel you should keep the spring as long as possible for the best ride. Lowering blocks yield additional drop w/no effect on spring rate or shock travel so they should definitely be considered.

The 1.5" block & drop spring combo sounds like the best option. The 2" blocks would also work, but you need to know there could possibly be consequences w/that option.

I would prob do the shock relocation brackets or you could tweak the factory shock mounts to ensure the shock angle is as close to stock (optimum) as possible....

http://67-72chevytrucks.com/vboard/s...d.php?t=359399

[loridr]

Scoti,

Appreciate your help. Sounds like the way to go is:

1.5 blocks
4" springs
adjustable panhard bar
relocate shocks

One last question (at least until my brain starts doing another burnout )

What is the "optimum" shock angle? As close to vertical as one can get?

My dad and brother have been in the aftermarket leaf spring business all their lives and say that the best setup is one shock in front of the axel and one shock to the rear of the axel; that’s the setup on my Toyota Tacoma but it would look like crap on a hotrod .

Btw: believe it or not, Posies Superslider is my dad’s design, he basically gave it away to Ken.

[SCOTI]

Originally Posted by loridr

Scoti,

Appreciate your help. Sounds like the way to go is:

1.5 blocks
4" springs
adjustable panhard bar
relocate shocks

One last question (at least until my brain starts doing another burnout )

What is the "optimum" shock angle? As close to vertical as one can get?

Cool deal about your pops. I feel as close to vertical within the spacial constraints is the way to go. I seem to recall reading 35° is about where the shock starts to lose leverage.

I suggest using a long/super Panhard bar set-up & high quality shocks (KYB GR-2's on a budget; Bilsteins otherwise) for best results.

[loridr]

Originally Posted by SCOTI

Cool deal about your pops.

He's a cool dude, holds 19 patents on various leaf spring suspension designs and components including what I believe was probably the first helper spring setup, the "Stanley Stabilator".

Anyway, thanks again for your help.

Steve

[vin63]

Originally Posted by loridr

So that I'm clear on my understanding of the implications of blocks: they essentially push the trailing arms down towards the ground and decrease the clearance between the trailing arm (actually the bottom of the U-bots) and the ground, correct?

Here's a visual...