do it yourself heavy duty lowering blocks

[SELLERSRODSHOP]

thought i would post this up if anyone else wanted to build something a little bit sturdier than the cast, hollow, made in taiwan lowering blocks on the market. i started by doing a little shopping in the cutoff bin @ metal supermarket & found a length of 2.5"x2" solid aluminum stock long enough to make 2 pair (i need to drop the 36 p/u rear too). cut the stock to the length of the mounting pads on the rear, in my case 4.75", mark the center of the block, chuck it up in the drill press & drill a 1/4" pilot hole completely thru the block.

on one side, using the 1/4" hole as a pilot, drill approx. 1/2" deep with a 9/16" bit. this will be the centering hole that fits over the pin in the leaf spring.

flip it over & drill the other side approx 1.25" deep with a 15/32" bit. (like my high dollar depth guage??)

next thread the 15/32" hole with a 9/16"x12TPI tap.

find a couple 9/16"x12 x2" long bolts. any length will be fine as long as it has an unthreaded section under the head. thread the bolt as far as it will go & mark it taking nota as to how many threads are between the block & unthreaded section. this is how much you need to shorten the threaded end of the bolt.

cut the excess length off the end & reinstall into the block & tighten down.

now simply cut the head off the bolt & bevel the edge leaving approx 3/8" of the unthreaded portion of the bolt as the alignment pin for the rear end pad.

these are much sturdier than the hollow ones & after lowering, if i need to change the pinion angle of the rear, i can simply chuck them up in the mill & machine to the desired angle which eliminates the need for additional shims. to further strengthen things up, i had the new u bolts made from 1/2" stock, which is heavier than the original 7/16" bolts, so i'll have to mill out the holes a little in the bottom shock mount plate.

the whole project took only an hour to complete & with the high grade of aluminum, i have the option of ball milling the sides & polishing them up for a "show car" appearance. i probably wont do this on the mustang, but will on the 36. (i'll post pics of those when they are finished)

 

[PJ Moran]

Lowering blocks are not a good way to lower a car because they:
1) may induce wheel hop into a car that didnt' have it or
2) aggravate already existing wheel hop problems.

But, if you're going to go this route, I see nothing wrong with the "cast, hollow, made in Taiwan" blocks currently on the market (except for the Taiwan part). Sometimes the layman misinterprets "hollow" as "weak". Granted, they're "weaker" than solid blocks, but they're still more than adequate for the job. So, I wouldn't be in a big hurry to find a "sturdier" alternative when it will do nothing but lighten your wallet, take up your time, and satisfy a false concern. Has anyone ever heard of one of these things failing?

I'm not a machinist, so I can't speak to the difficulty of milling an angle into one of those cast pieces. I don't see the issue, though.

I wonder if those blocks are saw cut from an extrusion, as opposed to being cast. There's a big difference.

 

[66gt350]

Has anyone ever heard of one of these things failing?

Didn't Johnpro have one fail on Scary? Or is my memory as bad as I think???

 

[johnpro]

Lowering blocks are not a good way to lower a car because they:
1) may induce wheel hop into a car that didnt' have it or
2) aggravate already existing wheel hop problems.

...

Has anyone ever heard of one of these things failing?

Yes, I have heard of one, I have experienced it, and got the t-shirt. I should have taken pictures of the broken pieces I pulled out. It was downright scary that I was still driving the car like that. I just couldn't figure out why my rear end was literally trying to push the car sideways. It was because after some of the chunks of the hollow blocks fell out, the entire rear was loose.

I put new hollow ones in, because the car MUST be lowered. I have new 5-leaf standard eye Grab-A-Tracks in the rear and they left WAY too much distance between the top of the tire and the wheel well. I didn't have any wheel hop before adding the lower blocks, and still don't today. Now, mind you, I have no traction, either with the 275/50/15 BF Goodrich Radial T/A's, but no wheel hop.

Personally, I REALLY like those solid lowering blocks!! As I was reading how he made them, I just kept thinking WOW, I WANT some!

 

[SELLERSRODSHOP]

yes, i too have had the cast blocks fail on a couple of occasions over the years. i think the main failure point is the fact that the castings aren't precise. on most i've seen the hole in the bottom & the button on the top are actually tapered & not a "square" hole, which when under stress, have play in them until they stress & fail.

i also don't particularly care for using blocks, but with leaf spring cars (really necessary on the older rods), it's hard to get the ride height precise without some sort of block shim etc. right now, my funds are focused more on finishing my 36 p/u so at the moment couldn't justify purchasing new springs & having them de-arched to the desired ride height. that will come later on when funds & free time are focused on the mustang.
also, price wise, i have $20 invested in these along with one hour of labor time, so at about the same cost, i would much rather have something that is a little sturdier.

 

[stanger69]

man, that's looks great on your car and a nice write up on the how to. I was wondering, what is the average price for having the de-arching process on leaf springs?? and who would I go to in order to have this done?? Thanks

 

[70_Fastback]

Pretty trick! I like it.

 

[66notch]

Blocks huh?! Seems to be some question if blocks are the best choice to lower.

So if I don't use blocks what choice do I have to lower my 66?


And appears that the shocks are extended a bit more than the hight of the block (that hypotenuse triangle thing).

Do I need to renew shocks when lowering with blocks?