Lowering blocks

[340runner]

Hi, I'd like to lower my car about half to 1 inch inches, the stance right now looks kind of weird in my opinion with such a short tire, 295/50 but I can't really go to taller tires because of close ratio a833 trans and 3.55s, any taller and my mild ish 340 is slow off the line

Will I run into issues with going through with lowering blocks? The main thing I would be worried about with it is pinion angle, don't want to create issues with it.

Don't really have a complete picture, this is the closest i have, from when my slipping 727 finally gave out in a McDonald's drive thru. It got the original a833 back in it though, I don't honestly know why the previous owner gave it a 727 that by time I got it was already slipping so bad I couldn't break the tires loose

 

[340runner]

Id also like to go to shorter front tire, it's on a 255-60-15 which is taller than the rear, weird also. I'd like to go to similar to stock front height, maybe also width while maintaining the rear tire size

 

[Kern Dog]

I had one inch lowering blocks in my car for years....

I took them out a few months back because I wanted to raise the car up a bit.
There were never any problems with drive line angle, pinion angle, vibrations or anything.

 

[nitro_rat]

A 1/2" or 1" block shouldn't hurt anything. If you want just a 1/2" I would hack them out of a piece of 1/2" steel, drill a center hole, and bolt them into the spring pack.

Here's my old '67 Dart before the altitude adjustment...

And after...

I think I actually cut a 2" aluminum block down to a 1" for this one. I definitely don't recommend trying that at home unless you have a mill to make the cut square.

 

[j-c-c-62]

Performance wise wheel hop tendencies are likely your first handling concern or indication and can occur under both acceleration and/or braking, and are directly related to the height of the spacer used. Usually up to one 1" is tolerable, anything larger problems can arise. The taller spacers add leverage to the spring resulting in spring wrap up promoting wheel hop. There are other concerns, but they are less obvious.
They are the fastest easiest way to change cars stance, but there are technically better ways.

 

[340runner]

Performance wise wheel hop tendencies are likely your first handling concern or indication and can occur under both acceleration and/or braking, and are directly related to the height of the spacer used. Usually up to one 1" is tolerable, anything larger problems can arise. The taller spacers add leverage to the spring resulting in spring wrap up promoting wheel hop. There are other concerns, but they are less obvious.
They are the fastest easiest way to change cars stance, but there are technically better ways.

Okay, I don't have any wheelhop right now, but i also don't have sticky tires but plan on getting some bias slicks. I hope that I don't introduce any, I ripped out my adjustable pinion snubber, as it wasn't really doing much on my street tires.
Are there any other better ways to get my desired stance without getting different leafs, everything else aside from blocks
seems crazy expensive

 

[340runner]

I had one inch lowering blocks in my car for years....

View attachment 1790447

View attachment 1790448

I took them out a few months back because I wanted to raise the car up a bit.
There were never any problems with drive line angle, pinion angle, vibrations or anything.

You wanna send them my way? Just kidding... only kind of

 

[j-c-c-62]

I took a semester in college in Technical Letter Writing many decades ago. I can't believe I aced it.
I attempt to keep/maintain/improve any of those skills that remain any chance I get.
I'm also a big believer one understands a topic proficiently when they can explain it to their grandmother, according to Einstein.

So here goes, the OP should consider if this applies under "other concerns" I mentioned above.
Imagine an imaginary line drawn from the front leaf spring pivot point back to the center of the axle centerline, where it is or is relocated to by spacer blocks.
On a live axle those lines would exist on each side.
If the lines were perfectly horizontal, when the car turned and leaned whatever amount the speed/cornering generated,
the outside leaf would compress, causing the outside imaginary line to arc upwards, pulling the rear axle centerline slightly forward on that side.
Now the inside leaf would likely droop an exact opposite amount down, also pulling that rear axle centerline the same amount also forward.
The end result is the rear axle would not change the rear axle thrust angle that might cause the rear to steer the car as the car leans, rather than just follow it.
When you add spacer blocks, that horizontal imagery line no longer results in equal and opposite motion of the rear axle, without inducing a thrust angle.
If the imaginary lines tilt down towards the rear of the car, steering induced leaning promotes oversteer by the new thrust angle steering wider in the turn.
If the imaginary lines tilt upwards towards the rear of the car, steering induced leaning promotes understeer by the new thrust angle steering tighter into the turn.
"Promotes" here does not mean exactly cause, as it might just reduce a opposite previous handling tendency.

How did I do?

 

[6PKRTSE]

Go with the solid blocks. Depending how cheap the hollow style spacers quality is they may start to collapse after miles of driving. I have solid 1" spacers on my Caltracs car and also welded them in 100% all the way around to the axle perches.

 

[j-c-c-62]

Okay, I don't have any wheelhop right now, but i also don't have sticky tires but plan on getting some bias slicks. I hope that I don't introduce any, I ripped out my adjustable pinion snubber, as it wasn't really doing much on my street tires.
Are there any other better ways to get my desired stance without getting different leafs, everything else aside from blocks
seems crazy expensive

Moving your front leaf pivot point with new hangers if possible, changing leaf's arch, shorter rear spring hangers but the effect is geometrically minimal, and lastly changing wheel/tire size.

 

[340runner]

I took a semester in college in Technical Letter Writing many decades ago. I can't believe I aced it.
I attempt to keep/maintain/improve any of those skills that remain any chance I get.
I'm also a big believer one understands a topic proficiently when they can explain it to their grandmother, according to Einstein.

So here goes, the OP should consider if this applies under "other concerns" I mentioned above.
Imagine an imaginary line drawn from the front leaf spring pivot point back to the center of the axle centerline, where it is or is relocated to by spacer blocks.
On a live axle those lines would exist on each side.
If the lines were perfectly horizontal, when the car turned and leaned whatever amount the speed/cornering generated,
the outside leaf would compress, causing the outside imaginary line to arc upwards, pulling the rear axle centerline slightly forward on that side.
Now the inside leaf would likely droop an exact opposite amount down, also pulling that rear axle centerline the same amount also forward.
The end result is the rear axle would not change the rear axle thrust angle that might cause the rear to steer the car as the car leans, rather than just follow it.
When you add spacer blocks, that horizontal imagery line no longer results in equal and opposite motion of the rear axle, without inducing a thrust angle.
If the imaginary lines tilt down towards the rear of the car, steering induced leaning promotes oversteer by the new thrust angle steering wider in the turn.
If the imaginary lines tilt upwards towards the rear of the car, steering induced leaning promotes understeer by the new thrust angle steering tighter into the turn.
"Promotes" here does not mean exactly cause, as it might just reduce a opposite previous handing tendency.

How did I do?

I understand, I think i do anyways, but as you said 1 inch and below shouldn't do too much hopefully so I'm gonna hope and pray

 

[j-c-c-62]

I understand, I think i do anyways, but as you said 1 inch and below shouldn't do too much hopefully so I'm gonna hope and pray

I would, the qualifier here is mostly impacted is what was you starting point, say if you were a 1/2 inch low to start and now a 1" block makes you 1/2" high on your imaginary lines, you are in range I would guess of being acceptable. Keep in mind this is only factor when a car leans for whatever reason, which can occur in the 1/4, it's more of a big deal in autocross, RR, on ramps, etc.

 

[GTX JOHN]

I would strongly suggest you recheck pinion angle after a 1 inch spacer.

 

[Kern Dog]

Why? The spacer mimics the suspension being lower. If the mounting points of the leaf springs were changed, that would affect the pinion angle.
I've changed the mounting position at the front of the leaf spring using hangers like these:

That lowered the car but didn't cause any issues. I don't drag race though so my springs don't see the same shock. I have short and wide tires for better handling. They don't grip in a straight line like slicks or a taller tire with a thicker sidewall. Better traction may have highlighted an issue if there was one.

 

[j-c-c-62]

I just can't leave well enough alone.

On pinion angle, seems like this was already covered here and put to rest, there is no reason not to check it pre and post and not difficult or complicated. to do. I can't see it being an issue in the OP's application with only a 1" change UNLESS it is off to start with. Wedge shims, or use of a mill will achieve the angles needed for correction.

 

[PurpleBeeper]

Hi, I'd like to lower my car about half to 1 inch inches, the stance right now looks kind of weird in my opinion with such a short tire, 295/50 but I can't really go to taller tires because of close ratio a833 trans and 3.55s, any taller and my mild ish 340 is slow off the line

Will I run into issues with going through with lowering blocks? The main thing I would be worried about with it is pinion angle, don't want to create issues with it.

Don't really have a complete picture, this is the closest i have, from when my slipping 727 finally gave out in a McDonald's drive thru. It got the original a833 back in it though, I don't honestly know why the previous owner gave it a 727 that by time I got it was already slipping so bad I couldn't break the tires loose

Hi, I'd like to lower my car about half to 1 inch inches, the stance right now looks kind of weird in my opinion with such a short tire, 295/50 but I can't really go to taller tires because of close ratio a833 trans and 3.55s, any taller and my mild ish 340 is slow off the line

Will I run into issues with going through with lowering blocks? The main thing I would be worried about with it is pinion angle, don't want to create issues with it.

Don't really have a complete picture, this is the closest i have, from when my slipping 727 finally gave out in a McDonald's drive thru. It got the original a833 back in it though, I don't honestly know why the previous owner gave it a 727 that by time I got it was already slipping so bad I couldn't break the tires loose
View attachment 1790444

Well, I’ve been running 2” lowering blocks for about 7-8 yrs and they have worked great. The blocks do not affect your pinion angle. The “2-hole” front spring perches DO change your pinion angle (that’s why I went to lowering blocks). I’m running some super cheap, off-the-shelf Autozone/O’Reilly/etc. truck “lift blocks”, which on a Mopar are “lowering blocks”. It’s nearly a perfect fit. I think I had to shrink the pins in the blocks a tiny bit (sandpaper) where the leaf spring locator pins on the blocks go into the spring saddles in the rear end. There are only 2 issues… 1. They won’t clear old school “slapper” traction bars (I went with an adjustable pinion snubber). 2. I had to substantially modify the pinion snubber to clear. I basically cut the adjustable part of the snubber (inner & outer box steel with holes for the locking pin) AND I added a smaller rubber bumper that I cut in 1/2. Done. No wheel hop. Pinion snubber maybe 1” from floorboard and it doesn’t hit the body (unless I floor it). There might be a clearance problem on a Hemi car since they get an extra plate welded in there, but neither of us has a Hemi car, so you’d be OK. The blocks cost like $35-$40 and come with longer U-bolts

 

[Mopar Miki]

Using the front spring hanger to lower the car is a better fix than lowering blocks because it improves the roll ctr of the car. Not hearsay, something i learned with the technical support of Bill Reilly at RMS while i was setting up cars to go faster than everyone else

 

[toolmanmike]

I just can't leave well enough alone.

View attachment 1790504

On pinion angle, seems like this was already covered here and put to rest, there is no reason not to check it pre and post and not difficult or complicated. to do. I can't see it being an issue in the OP's application with only a 1" change UNLESS it is off to start with. Wedge shims, or use of a mill will achieve the angles needed for correction.

Those are a solid looking piece.

 

[68 Sport Satellite]

I had one inch lowering blocks in my car for years....

I took them out a few months back because I wanted to raise the car up a bit.
There were never any problems with drive line angle, pinion angle, vibrations or anything.

KD, do you have before and after side view photos of your car to show the comparison?

 

[BSB67]

Saying that lowering spacers do not change pinion angle is incorrect.

Agree that the angle change from 1” spacer will be small and likely fine if the angle was reasonably correct to begin with.