Finalizing Suspension

[RGV72BLAZER]

Need help finalizing my suspension setup for my '72 Blazer that will be running 44s.

(Front) I plan to use 12" springs from a 73-87 Chevy with an ORD shackle and 1" zero rate. That nets about 13-13 1/2". Then I plan to build 2" drop hangers which hopefully will give me the 15" of lift that I want. A. Since I'll be using springs for a 73-87 Chevy, which are longer than my original springs, will this give me a bit more lift? B. What angle should I put my shackle at? Or will that depend on suspension travel (which won't be much, but I just want enough so that I won't rollover on curves at the mall )

(Rear) I will use 8" springs with an ORD 4" shackle flip, 6.0" HD shackle, and 1" zero rate. This gives me about 15" of lift also. C. With this setup will the tires be in the same place as before? Or will they be more forward or backward? D. Should the shackle be at a certain angle or at a 90*?

Would like to run rockwells instead of my D60/14FF combo that is sitting & waiting for a suspension. E. Would I have to move the spring perches in on the rockwells with a WMS of 72"?

Pinion angles, driveshafts, etc. are another story. Suggestions & constructive criticism welcome. Thanks.

 

[Greg72]

Up front:

I'd suggest that you drop a plumbline from your frame to the centerline of your existing axle and mark on the frame where that point is. Since you're using longer springs AND building custom hangers, you can compensate for the axle shifting by building the front hanger longer if necessary... just check where your axle is landing relative to that first reference line you marked on the frame and adjust accordingly.

As for shackle angles....NO 90* is not a good angle, but then again with 12" lift springs you are in kind of a different world anyway. Ideally, you want the angle (and length) of the shackle to be setup so that the spring can "grow" as it compresses. Measure between the spring eyes and write down that number.....then measure by running a tape from eye to eye AROUND the curve of the spring. Theoretically, if the spring could be flexed enough to flatten out completely, that's the length it would be.

Subtract the second number from the first number and you'll know how much "growth" is theoretically possible....that will help to determine your shackle lengths. Playing around with all of this on graph paper with a compass will probably help too.

Take your time, and figure things out BEFORE you start cutting and welding. Slapping on 15" of lift and 44's isn't a "weekend project".....there's plenty involved getting it done correctly. Being able to still attach a front driveshaft when you're done will be a challenge too!!!

 

[RGV72BLAZER]

thanks Greg, very helpful. i'll probably just print this page out so when i get to working i can have it there to read. as for driveshafts, that's one reason i'm leaning towards rockwells.