Are all Longhorn frames the same?

[rs74]

I have started to look for a nice clean C30 to buy. I have come across a couple C20 Longhorns. I thought I had read that they had the same frame but wasn't sure if there was any variance in that. Are the C20 frames the same height and thickness of the C30? Does it matter is they are Custom Camper trucks or does the Longhorn make them a Custom Camper. Just wondering if I need to be taking the C20 LH into consideration along with the other C30 variations.