Bakerdude,
WOW, cruising at 80-90 it must be running better, congrats.

Heated Intake:
My Clifford is fine w/o heat but thats usually 50F or warmer outside here in Cali. It does hit a dewey 35F-40F in the winter and then its a little rough til it warmd up.

IIRC it can get a bit Brisk in Wyoming?
Yup, I'd really try for manifold heat of some kind.
The old Ford 4bbl spacer runs heater hose hot water thru it, but I dunno of any such 1bbl spacer.

OR, can you use closed air cleaners with a heat snorkel up from the exhaust for fall/winter/spring, and ditch those ugly things for summer?

JETS:
Thats not a huge step from .058 to .054, about right to see what the stopwatch says. How do U know its too rich?

You can also use Holley jets in those little Rochester carbs, just check clearance to the bottom of the bowl and file if needed.

HOWEVER- the numbers dont line up. If you have a .058 Roch jet, then a H64 Holley jet is about its equal. But for tuning, you can easily get any Holley jet so its way easier to tune.