Finding instant center on a 1960 Impala

[11thhourfabrication]

I am having some problems trying to find the instant center on my 1960 chevy sedan delivery (same as Impala). After plotting the points as best I could with the sheetmetal still on the car the lines for the upper and lower control arms do not converge but go off in opposite directions. I am using Global West UCA and LCA and a CPP dropped stock style spindle. Does anybody have any suggestions.

Thanks in advance

[David Pozzi]

If they don't intersect at all, then the roll center is at ground level. If the intersect point (IC) is on the same side of the car as the wheel being drawn, then the RC is below ground.

[11thhourfabrication]

Thanks for the reply. Let me see if I got this. Even though the lines through the ball joint and pivot rise up and never intersect the IC is at ground level? If that is so at what point on the horizontal plane do I measure the IC so I can finish the measurements for wheel rate?