54 & older 56 & up GM Pickup front Axle Differences

I know that it was transition time from 54 to 55 with GMC/Chevy pick-up trucks. I was wondering what differences or changes were done to the front I-beam axles and steering if any? Thanks

 

I have both (a 54 & 57) in 3/4 ton and a complete 1/2 ton suspension set up for the 55-59 and have never measured either but was told that 55 and up are wider and different spring spacing. it would only take a few minutes with a tape measure if no one comes up with a real answer

 

The frame rails on the earlier ones are not parallel, the front is closer together than the back. The 55-up trucks have parallel rails. The axle is wider on the newer trucks.

btw, the cutoff was midyear 1955, so you'll hear about 1st and 2nd series 55 trucks....

 

Thanks guys, I appreciate it. What about spring lengths? Are they different throughout those years? I'm building a gasser with a 54 front axle and would also love to know of a good spring supply house.

 

early front springs are 38", later ones are 44", so yeah there's a big difference

 

They use the exact same kingpin, but different size bearings. Also I think steering arms/ tie rod is different.