Lowering blocks/U bolts

SadbutTrue

Founding Member
May 1, 2002
2,390
4
49
Granada Hills, California
Anyone have opinions regarding lowering blocks? I am going to drop my car about an inch sooner or later, but I have fairly new (and stiffer than stock) leaf springs on the car and it'd be a shame to get rid of them already. Lowering blocks seem to be an option, but they also sorta... well... they do seem like a half-assed solution, to be sure. While I realize its not optimal, as long as there aren't any major risks and it won't completely mess up any aspects of the car's performance, they'd be a cheap solution until I have more money for rear leafs...

On a similar note, does anyone know where to buy longer/wider u-bolts? The ones I have around my 9inch now barely fit, and only do because we bent the hell out of them. I couldn't for the life of me find any new u-bolts that'd fit my car when I put the rear in, so i had to reuse the ones from the old 8 inch rear. If I got lowering blocks, longer/sturdier/wider u-bolts would be a necessity, so yeah, if you know where to get some let me know.
 
Anyone have opinions regarding lowering blocks? I am going to drop my car about an inch sooner or later, but I have fairly new (and stiffer than stock) leaf springs on the car and it'd be a shame to get rid of them already. Lowering blocks seem to be an option, but they also sorta... well... they do seem like a half-assed solution, to be sure. While I realize its not optimal, as long as there aren't any major risks and it won't completely mess up any aspects of the car's performance, they'd be a cheap solution until I have more money for rear leafs...

On a similar note, does anyone know where to buy longer/wider u-bolts? The ones I have around my 9inch now barely fit, and only do because we bent the hell out of them. I couldn't for the life of me find any new u-bolts that'd fit my car when I put the rear in, so i had to reuse the ones from the old 8 inch rear. If I got lowering blocks, longer/sturdier/wider u-bolts would be a necessity, so yeah, if you know where to get some let me know.

Lowering blocks can sometimes be a challenge because of slight curve of the spring in the application area. Aluminum tends to crack and steel also has issues. Mine are actually home made from polycarbonate and are holding up very well and allow for the flex needed.

If anyone interested I will try to get up a photograph. This is one of the items that we will be offering in 2008 providing a 1" drop.

I believe my longer bolts came from Speedway Racing Products. It has been awhile and am sure they could be ordered from perhaps NAPA and Currie Enterprises.

HistoricMustang
 
Here is pic of the aluminum 1" jobs i got from Mustang's Unlimited for about $50. They have been on for around 3 years and lots of hard launches at the track and i haven't had any issues w/ them thus far....

835961_102_full.jpg
 
Mustang Unlimited

Sent me the wrong parts. I ordered shock braces and u bolts and they wont fit my car for some reason. Was putting one of the new rear leafs on yesterday and had to use the old hardware to put it back together. The u bolts they sent me wouldn`t even fit the shock braces that came in the same box....
 
Napa should be able to get you the Ubolts.

Lowering blocks seem to get a bad name but honestly lots of cars run them. Just make sure you tightem them down well and put a lock washer on it. Id drive the car for a week and make sure they stay tight.
 
Sent me the wrong parts. I ordered shock braces and u bolts and they wont fit my car for some reason. Was putting one of the new rear leafs on yesterday and had to use the old hardware to put it back together. The u bolts they sent me wouldn`t even fit the shock braces that came in the same box....

A stock 65-66 needs a 2 5/8" spread. This is standard. So it's likely that someone changed the rear end along the way. As far as Ubolts are concerned, see if there's a "Spring Service" shop in your area. They can made in about any dimension needed. When I was running leafs, I had them bend 1/2" bolts instead of the 7/16 ones.
 
I guess I am knew to this whole lowering thing, but what are lowering blocks. How exactly do they work?

Is it safe for him to do that and drive on them without worrying?
 
I guess I am knew to this whole lowering thing, but what are lowering blocks. How exactly do they work?

Is it safe for him to do that and drive on them without worrying?

lowering blocks go between the axle and the leaf, thus raising the axle the height of the block, and lowering the car. as long as you dont use a block more than 2" thick, there are no problems with lowering blocks in daily driving, or any other use.
 
Does a 1" block directly mean a 1" drop? I would think slightly less. Thanks guys.

Yep, this makes sense with friction, spring compression, etc...............somewhat less than 1 inch.

Now, THIS is tech.

Kind of like if you cut a coil spring does it increase or decrease the rate. There have been fist fights over this one!

HistoricMustang
www.historicmustang.com
 
Torque = force x distance.

If you increase the distance betweeen the axle centreline and the spring (ie, with lowering blocks), you get an increase in the amount of torque being applied to the spring - simple math that cannot be disputed.

More torque applied to the spring = more wind up and potentially more axle snapping, diff destroying, gearbox exploding axle hop if your shocks aren't up to keeping everything together.

If you're casually driving, lowering blocks won't be a problem. Personally I wouldn't use them on a racecar. The cost of getting a set of springs exactly as you want them is a helluva lot less than replacing the aforementioned drivetrain items.
 
Torque = force x distance.

If you increase the distance betweeen the axle centreline and the spring (ie, with lowering blocks), you get an increase in the amount of torque being applied to the spring - simple math that cannot be disputed.

More torque applied to the spring = more wind up and potentially more axle snapping, diff destroying, gearbox exploding axle hop if your shocks aren't up to keeping everything together.

If you're casually driving, lowering blocks won't be a problem. Personally I wouldn't use them on a racecar. The cost of getting a set of springs exactly as you want them is a helluva lot less than replacing the aforementioned drivetrain items.

Great observation! That is why some flex is necessary in the early models. My ride was called the "Flexible Flyer".

My lowering blocks even have flex built in by using a "polycarbonate"!

Happy Motoring!

HistoricMustang
wwww.historicmustang.com