Best alignment numbers
 

Anybody have a good set of alignment numbers to take to my local shop. I'm running 33x10.50 BFGs on my 72 , stock axles with a 2 1/2" lift kit and a new redhead box with all new front end components. Time to get this puppy on the road

Re: Best alignment numbers
 

Don't waste your time going to a shop, do it yourself.
All that can be adjusted is toe-in. With 33" tires, aim for 3/16" toe-in.
If you want your truck to handle better, put a set of 3 degree caster shims in. From factory the trucks have around 3 degrees built-in, so adding these shims will give you a total of 6 degrees which is perfect for these trucks.
The camber also can't be adjusted (technically).
One last thing, make sure you have an anti-sway bar.

Re: Best alignment numbers
 

So do you put a camber adjustment ring behind the hub? I used the below for toe.

https://www.summitracing.com/parts/lro-diy-tst

Re: Best alignment numbers
 

Leave the camber alone. As I mentioned above, it's the caster you want to increase. Here's a link to what you need----->
https://www.summitracing.com/parts/wrp-800061

To set the toe, all you need it a tape measure. You don't need all these fancy setup jigs like the link you gave, just go off the tire tread.

Re: Best alignment numbers
 

Sorry I misread that. I might have to put those on mine.

Re: Best alignment numbers
 

It doesn’t seem the shims come in 3 degrees. Is 4 too much or 2 the better route?

Re: Best alignment numbers
 

I machined my own and I just made them 3 degrees. If you're going to do a lot of driving in 4WD, I would get the 2 degree wedges. If you do mostly street driving, then go with the 4 degrees. The reason I would only use a 2 degree wedge in 4WD is to try and reduce too much front u-joint angle.
The info I'm giving you is what has worked for me with my setup, and it made a huge difference in feel and drivabilty. I don't get that side to side wander anymore that these Blazers are famous for.
I'm also running 33" tires with a 2" lift, so our setups are similar. When I put the wedges in I also added a factory front anti-sway bar, so I believe it was a combination of the two that made all the difference.

Re: Best alignment numbers
 

Awesome thanks for the info.

Re: Best alignment numbers
 

Please let me know how you make out.

Re: Best alignment numbers
 

Will do. I’m hoping to get it running the next couple of months. It’s been sitting two years.

Re: Best alignment numbers
 

Tom Woods has the 3 degree shims, few other places as well. https://4xshaft.com/products/axle-shims

Re: Best alignment numbers
 

I probably need to do this to get rid of some wandering. I have 12.5 x 33 BFGs on mine. I'm assuming the thickest part of the wedge goes to the front, correct?

Re: Best alignment numbers
 

No, thick part would go to the back to increase caster.

Re: Best alignment numbers
 

I'm glad I asked...

Re: Best alignment numbers
 

Hemi, As much as you are not wrong, I feel there should be some time/effort spent figuring out where the caster is. Between the age of these trucks, swapped parts (especially a/m lift springs) ect. one could end up WAY off & just picking 3* may only be a start & if you are buying, why not get 5 or 6* shim if that puts you closer to the desired number? You sure dont want to be anywhere down around 0*.
A simple "C" shaped fixture made out of a couple pieces of scrap metal (to get around the bulge in the center of the knuckle) to sit on the knuckle at the ball joints & an angle finder will go along way to telling where you are. Lorne

Re: Best alignment numbers
 

Glad it helped. Note that while increasing the caster to 6-8 degrees like the newer straight axle trucks can be beneficial. It does point the pinion down and increase driveshaft angle. Can cause interference in the CV at lifts 4" and over. A CV actually has less max operating angle than a single u-joint. Good idea to check for binding at full droop (axle hanging) after changes are made.

Re: Best alignment numbers
 

I checked the factory numbers BEFORE I did any mods to get a baseline. My factory 1970 dana 44 had 3 degrees of caster and 1 degree of positive camber right from the factory. This was measured on brand new Tuff Country 2" lift springs.
I wanted a total of 6 degrees, and that's why I used 3 degree shims.
I checked the caster exactly like you mentioned, I measured from the top ball joint stud to the bottom stud with a small jig I made and a digital angle finder. I made sure the truck was sitting level before any measurements were taken. The camber was measured off of the rim lip. All measurements were taken with the full weight of the truck sitting on the ground.