Technical Radius Rods (TCI Frame)

Looking at the TCI website: 33-34 Ford Dropped Front Axle, 4 Link Rearend, there are several options for the front axle which seem pretty straight forward, but there is also an option for radius rods. According to the website, the chassis comes complete - so what are the optional radius rods?

Yes, I can call TCI tomorrow and ask - I got home too late today and figured someone on this forum would know.

Thanks

 

I think the option is hair pin style radius rods as compared to the standard four bars they sell.

 

Thank you