Rearend swap: 3:73 or 3:55?

Hey guys, I've got a guy selling me an old vnl cutoff with much desired 3:73 lockers. Was going to swap in the carriers, but my current ratio is 3:55. Ive been debating whether to use the 3:73 ring and pinion or take the extra work to go back to 3:55. Ive got a 99 vnl n14 celect plus 370/435 with 10 speed and 11r22.5. I will likely be getting into regional/otr flatbed, and I live in the Appalachian (eastern mountains) region, driving 70 mph.

Would i take much mpg hit, or is the extra grunt and maneuverability worth it? Or is it a wash? Been racking my brain on this stuff.

I definitely know one thing: that those tall geared megacarrier trucks are horrible on clutches

 

Ive got the FRO-15210C.

Yeah, looks like its a difference of exactly 71 rpm at 65 with 41 inch tires. 1400 for 3.55 and 1471 for 3.73. Given that cummins officially recommends 1450, 3.73 looks closer with those numbers

As for gear changes, 9th and 10th seems more optimized for 55 and 70 with 3.55 while 3.73 is more for staying in 10th 60-70. But 3.73 would be close to 1700 at 55 in 9th and 1250 in 10th. I wonder if thats ideal.

Also, I would think lower ratios would have a safety advantage descending hills as well.

Anybody really notice the difference?

 

Wow... The people have spoken!. I guess 3.73 it is! Funny thing... I was lucky enough to find a cutoff with lockers that just happened to be an old vnl. Didn't know till I got there. Its a little rough, but rebuilt lockers are worth more than $2500 alone.
I think these trucks really need them, and I wouldn't want to be without em. These tractors are so setback and nose heavy, they practically get stuck on concrete, lol. I live in a rough area. That thing will spin out before I even leave the state road!

I say they pay for themselves when I avoid paying for a tow. Every truck should have em by principle. Farm tractors do, why not road tractors?