“Early Roman Kings”‘ main rhyming pattern is the alternating rhyming abab as in its second verse

All the early roman kings
In the early early morn
Coming down the mountain
Distributing the corn
Speeding through the forest
Racing down the track
You try to get away
They drag you back
Tomorrow is Friday
We’ll see what it brings
Everybody’s talking
Bout the early roman kings

But there are interesting diversions from or exceptions to that pattern.  In the very first verse, “in” jumps in with “coffin” to create couplets:

Drivin’ the spikes in
Blazin’ the rails
Nailed in their coffins
In top hats and tails

In the middle of the third verse appropriately an internal rhyme appears with “lecherous” and “treacherous”

They’re lecherous and treacherous
Hell-bent for leather
Each of ’em bigger
Than all them put together

But the rhyme sound, the assonance namely, pushes forward with “Hell-bent,” “leather,” “them,” and “together.”

Indeed, Dylan’s rhyming bell still rings, like the bell in Breaking Bad:

I ain’t dead yet
My bell still rings
I keep my fingers crossed
Like them early roman kings

Live Version from just this past June 2014 with nice clear video (thanks to Ernest Habringer):