4.10 vs 4.56

[Itchy feet]

Originally Posted by arctictraveller

It really depends on your usage. I've got the 5.4 with 33in tires, but don't tow. I went to 410's and as you say, that brought it back pretty much to stock, since now my speedo is accurate to within 1mph or so. I drive pretty easy, but in the mountains I find that on the steeper hills I need to down shift unless I hit them hard and keep the RPM's way up, which doesn't seem to affect the engine at all. Unless you drive a lot at high elevations, pull a lot of hills or tow a bunch, 410's could be a good compromise. If you dislike downshifting, or want more power, going even deeper with the gears will certainly help at the cost of higher RPM 's on the flats.

By the way, you could buy my already rebuilt D60 with 410's and save some money in the process. https://www.sportsmobileforum.com/fo...oat-26330.html

this seems to be where im at as i posted before im more concerned about being underpowered in a 4x4 situation. do you have any problems there? or does that nominal difference in gearing not matter so much on the low end?

[keytothestone]

I have 5.4 with 4.56 9-10k rig never tow on 35s. Live right off hwy 550 in at 7k feet in Southern Co. Never driven one with 4.10. I need every ounce of RPMs to keep it at least 65 on the passes around here. Take it out of OD and I might eventually get up to 70mph. Couldn't ever imagine having anything less than 4.56. And thankful that was recommended to me. 4.88 is always a thought. Hope that helps

[Vanzila]

4.10 4.11 ish You will not be sorry. Your 5.4 will thank you for it.. Of course my 5.8 has more torque but I can tell you I was running 3:73's for the first 20 years or so. I would go for the 4:10

[Vanimal]

If I am not mistaken, I believe your initial post was questioning about whether you should go 4:10 or go 4:56 with 30.5's? You are converting to 4x4 and your conversion company has recommended 4:56 as they do all their conversion customers. If this is how I read your post. If so then my reply is you have another option. 4:30 is a good choice and available for the rear Dana 60 from Yukon. Many front dually axles came with 4:30 so you do not have to search far and wide. It was a Ford option for the front Dana 60 so they can order your front axle with a 4:30. This would leave only the rear needing a gear swap, if you have a Dana 60 rear.
I like the 4:30 with my 35's and the 7.3 Diesel. I think 4:56 would have been too high and 4:10's was well not great with 35's although I drove it for 20 years with 4:10's. I think with your van with a 5.4 extra weight, now 4x4 and 30 + tires you would be happy with 4:30. I am and believe it or not I can tell the acceleration difference but not the RPM difference!

Edit correction: I just reread your post and you will be going to 35's in that case I believe you'd be happier with 4:56 4:88, the 5.4 will fall short, if you had the 5.8 then 4:30 could work!

[vintageracer]

All everyone talks about his how underpowered the 5.4 engine is under normal circumstances and you are now adding all the weight of the 4WD conversion and bigger tires.

4.56 gears will make you and your engine much happier campers!

[mk216v]

Some helpful links;

Gear ratio calculator;
https://tiresize.com/gear-ratio-calculator/

Anyone looking for 4.56+ ARB front locker;
https://www.sportsmobileforum.com/fo...ars-25533.html

[MaineWildlands]

I know you have a gas engine and the below info is for a diesel, but a secondary overdrive could compensate for lower gearing ratios in the axles.

I have a 2002 E350, weighing in around 9200lbs, and with a 7.3 with 4.10 gears, running 285/75/16 (34 inch) tires. When running on highways, at 65-70, with the normal transmission and gearing, you're turning above 2k RPMs, and missing that fuel economy. I have a Gear Vendor secondary overdrive that provides a half step gearing for each gear (turns 5 gears into 10), and in overdrive plus the gear vendor step up, that allows me to cruise at 70mph at 1700 RPMs.

Not a cheap solution, but a solid one that helps with low gear crawling, as well as high speed highway travel.

[Itchy feet]

thanks for all the input. I think I will be going with 4.10 since all the calculations I make brings the rpms back to stock. and coming from a 4 cylinder 87 Toyota I am fine with the power output. when it comes to highway speed im more concerned about mpg than being able to go 70 up the hills. hope I don't regret it. o and my new axle is also 4.10 that also plays a factor only have to change one

[Zane]

Originally Posted by MaineWildlands

I know you have a gas engine and the below info is for a diesel, but a secondary overdrive could compensate for lower gearing ratios in the axles.

I have a 2002 E350, weighing in around 9200lbs, and with a 7.3 with 4.10 gears, running 285/75/16 (34 inch) tires. When running on highways, at 65-70, with the normal transmission and gearing, you're turning above 2k RPMs, and missing that fuel economy. I have a Gear Vendor secondary overdrive that provides a half step gearing for each gear (turns 5 gears into 10), and in overdrive plus the gear vendor step up, that allows me to cruise at 70mph at 1700 RPMs.

Not a cheap solution, but a solid one that helps with low gear crawling, as well as high speed highway travel.

Will this set up work with a transfer case?