Global West Suspension manufactures offset upper control arm shafts:
Why use offsets?
Offset upper shafts are used for several reasons:
* Repair alignment because of frame damage or frame. sag.
* Repair alignment do to ride height change.
* Fine tune alignment for racing or performance street applications.
For most conditions offset shafts are used for frame issues. They generally give you about 1-1/4 degrees of addition adjustment. However for us in the performance world, they are perfect for getting the best possible alignment using stock suspension.
One of the keys to better tire life and performance on these older muscle cars is to increase caster and induce some static negative camber. In fact you want to do this because more caster is going to give the car straight-line stability, faster steering response, and greater feel. Then add some negative camber to the mix and your tire life will improve. The offset shaft will allow you to do that.
Generally speaking whenever we are rebuilding a stock front end and it is within the budget, we will install offset shafts every time.
All shafts are made out of billet steel and are supplied with hardware for the shaft, but not for the frame.
Offset shafts generally give you about 1-1/4 degree change. All shafts are made out of billet steel and are supplied with hardware for the shaft, but not for the frame. The shaft is zinc coated for corrosion protection. The shaft is made to accommodate a 5/8 fine thread locking nut rather then a 3/8 bolt that the factory shaft uses to hold the bushing in place. Generally the bolt has a tendency to back out over time.
As for installation, you should install the offset shaft so the tire will be pushed out of the fender, away from the motor. The engraved words Global West face the motor side.
However for road racing applications, it will be most likely the opposite.
Most common applications that use 702 offset shafts.
The following chart gives you factory alignment settings for the tires of that time. We are providing this information so you can judge where you need to be. I would not recommend using factory settings on todayís tires.
Original Factory settings: NOTE - (Measurements are in degrees).
67-9 Camaro/Firebird ---- Caster 0 to 1P ---- Camber 1/4N to 1/2P ---- Toe-in 1/8 to 1/4
64-72 Chevelle/GTO/Skylark/A-bodies ----- Caster 1-1/2 N to 1/2 N ----- Camber 0 to 1P ----- Toe-in 1/8 to 1/4
72 Monte Carlo ---- Caster 1/2N to 1/2 P ---- Camber ---- 1/4P to 1-1/4P ----- Toe-in 1/8 to 1/4
68-72 Nova ---- Caster 0 to 1P ---- Camber 1/4N to 1/2P ----- Toe-in 1/8 to 1/4
73-74 Nova ---- Caster 1/2N to 1-1/2P ---- Camber 1/2N to 1P ----- Toe-in 1/16 to 5/16
The alignment we recommend for the cars listed using factory stock components are as follows. Note: The only way you will get the following numbers is if you are using offset shafts. You should also know that depending on the frame, you could have a variable to our exact numbers. Try to get as close as you can.
Todayís recommended settings
67-9 Camaro/Firebird --- Caster driver side 3P ---- Passenger 3-1/2P ----- Camber both sides 1/2N ---- Toe-in 3/32 total
64-72 Chevelle/GTO/Skylark/A-bodies --- Caster Driver side 2-1/2P ----- passenger side 3P ----- Camber 1/2N to 3/4N ----- Toe-in 3/32 total
72 Monte Carlo Caster Driver side 2-1/2P ---- passenger side 3P ----- Camber 1/2N to 3/4N ----- Toe-in 3/32 total
68-72 Nova--- Caster driver side 3P ----- Passenger 3-1/2P ----- Camber both sides 1/2N ----- Toe-in 3/32 total
73-74 Nova ----- Caster driver side 3P ----- Passenger 3-1/2P ----- Camber both sides 1/2N ----- Toe-in 3/32 total
After the alignment, you should notice the number of shims between the upper arm cross shaft and frame will be greater in the rear then the front. The more shims in the rear increases caster and yes adds some negative camber, however the camber can still be set to spec.
As for the camber setting, the older cars roll positive which means as the tire goes up into the fender, the tire tilts out of the fender at the top and increases outside tire wear. Almost all of the specifications call for a positive camber setting. You do not want to do that, you need negative camber. Generally 1/2 a degree of negative camber is adequate for most driving applications (racing excluded). This will reduce outside tire wear and will not increase the inside tire wear.
We manufacture tubular control arms that have different alignment specifications then whatís on this page. The specís we call out are totally different because we are working of a different length control arm. The arms will increase the performance over stock dramatically.