Rear axle ratios and impact on towing

Ivylog wrote:
When we only had a three speed tranny without OD axle ratio was very important. Unfortunately many have not figured out with just a 4 speed pulling a heavy trailer you do not need a 4.10 as keeping it out of OD and direct (the best gear to tow in) you have a 3.73. These same ones then say but off the line you need the 4.10 and with a clutch that might be true but with a torque converter... give me a break.
Not sure you need 8 as I love my PSD with a manual 6 speed. Pulling I use 5 of them unless I'm on a hill and then use the low hole to get started. Around town it becomes a 3 speed.
OP, for what you are towing I do not see any problem with a 3.09 by keeping it out of OD or on a good hill one gear lower, but you have to lift your arm and select a different gear. I would nor call that having to work.:W

Don't disagree with anything you said (and btw couldn't be more jealous of your 7.3L/handshaker 6) but it is interesting to note how much of a bump the manufacturers sometime give on tow rating due to a different axle gear.

My 2008 F250 is rated for ~9200lb with the 3.73, yet ~11200 with 4.10s. IIRC the GM twins have a similar gap, perhaps even larger.

I switched from 3.73 to 4.30 and I would do it again; it completely changed the feel and driving dynamic of my truck. It's almost as if my 5.4L whispered "thank you, this truck's heavy and I'm a little V8" LOL