how to detect what year chassis you have?

[drivea55]

Hey guys,

I am usually over at the 47-59 section cause my cab is a 50. I was told it is sitting on a 72 chassis.

I would like to buy drop spindles but am told that 71+72 are different cause the ball joints are different sizes.

I have 4 wheel drum on 6 lug axles, coil springs in the rear, no leaf.

What is the best way to determine the year?

I did notice some numbers stamped on the pass. outer frame rail. not sure if that will help any.

thanks in advance for any help in this matter.

Brian