Suspension Height Math

Suspension Height Math

Suspension height after removing factory blocks

A common question we receive is how tall will my truck be after adding the shackle reversal and or drop main eye? That usually prompts us to ask some follow up questions like:

Is your truck stock height now?

Does it have a factory suspension block? If so how tall is it?

Are you looking to keep your factory block or remove it?

Are you going to be adding lift springs?

What height are you trying to end up at?

Since everyone's build is a little different each of these answers is going to be different. The majority of these builds can be boiled down to a common goal, a better ride. The better ride can be achieved by using the least amount of block and lowest spring height while still reaching your overall desired truck height.

The taller the block the more chance of axle wrap and the taller the lift spring the stiffer it will be (generally speaking).

Suspension Scenarios 

To help with the suspension math we are going to give some word problems and their answers (fun right!).

Jim has a 2001 Dodge 2500 with a 6" Tall factory block. Jim is wanting to remove the block to help the axle wrap he experiences towing and from his powerful Cummins. He is wanting to know what brackets to use in order to keep his stock height after removing the block. 

  • Answer: To make up the height of the 6" Block that Jim is removing he should use both the 2" drop main eye hanger and 4" shackle reversal. The cool part of this combo is it will keep everything in the stock location. So the math problem looks like -6" Block removal + 2" main eye + 4" reversal = 0" in height changed. 

Jerry has a 1975 Chevy K5 blazer. Right now it is on stock suspension with no blocks. He is adding a 2" lift leaf spring on the front and wants something to lift the rear with a little rake. He is wanting lift in the back without sacrificing ride quality. 

  • Answer: Since he is wanting a stock like ride in the back he is opting for one of our 3" shackle reversals. This will put him at 2" of lift in the front and 3" of lift in the back. The math works out to 0" (stock height) + 3" shackle reversal = 3" of lift above stock.

Jeff has a 2015 Chevy Silverado 1500 with a 6" lift that uses a 6" block in the back keeping his same height. He is wanting to remove as much block as possible because they are hard on his springs. He is also not wanting to do the work of replacing his springs.

  • Answer: Since this generation of truck has welded main eye hangers his only option is a shackle reversal. For Jeff's model truck we have a 5" shackle reversal. For a total of 6" we recommend using a 1" lift block (luckily you can get these from z71 packages). So the math works out to be -6" Block removal + 5" Shackle reversal + 1" block = 0" Change. When using just the reversal we recommend using one of our axle relocation plates to re-center the axle in the wheel well. Also a degree shim to adjust pinion angle. 

Joe has a 1986 Dodge Ramcharger that is stock height with a 4" factory block in the back. Joe wants 6" of lift but does not want to buy new leaf springs as he just paid for new OEM style leaf springs in the back. 

  • Answer: Joe is going to leave his factory block and leaf springs in the truck. He is going to use our 2" drop main eye and 4" shackle reversal for a total of 6" of lift. So the math works out at 0" stock suspension + 2" drop main eye + 4" shackle reversal = 6" total lift height. 

John has a 1997 Dodge 1500 with the factory 4" Block in the back. The truck is at factory height right now but he would like to lower it 2".

  • Answer: John elected to remove the factory 4" Block and use our 2" Drop main eye to result in the truck being 2" lower in the back. The math works out at -4" block + 2" drop main eye = -2" height.  Since only the 2" drop main eye is being used we recommend using a set of our axle relocation plates to center back in the wheel well. Also a degree shim may need to be used to adjust pinion angle. 


As you can see this list can go on and on with numerous possibilities, but hopefully will help answer questions you may have. We are also just an email away to help out with your specific project!! 

Back to blog