Straight Axle Caster Deg.

What is an acceptable amount of pos. caster for a solid axle set up?I have 15 deg. now and the car has a severe wobble when hit a bump at speed.The factory spec. for the axle is 2-4 deg. pos

 

I'm running 7 degrees on mine with no problems.

 

No two are the same as it also has to do with the center of gravity of your car/engine. 8-10 for the street and 10-12 if you're racin an goin fast.
You'll just have to try several settings.