Hey guys, I have been debating on this I have a 351/E4OD in my 96 with 3.55s towing it does okay but think it would work it easier with 3.73s.
Is this true?
from the ratio calculators its like a 200rpm diffrence at road speed ?
better low end grunt over the 3.55s?

Thanks guys
Curtis

 

Yes it will tow better. But if you tow often 4.10s would probably be better. If I was going through the effort and spending the money on new gears I would definitly put 4.10s in.

 

What size tires? 3.73 just restores the overall gear ratio to near stock if you have 31" tires, so in that case you'll need 4.10 just to see an improvement in pulling power.

 

3.55 to 3.73 isn't enough of a jump to justify the cost IMO. Don't do it or put 4.10's in.

 

Can't agree more.

 

Well a 265/75R15 is a 31, last weekend I had our 3400lb tri-axle trailer with a 4600lb car on it 351 towed it fine. Figured if i could better it without killing mileage 4.10s that thing will go from 16-19city/19-24hwy to 10, if I am going to do that ill get a 460 and loaded or not get 12mpg.

Curtis

 

i am doing the same thing , not for towing though, my truck was fine with the 355 with the 32's , with the 305's it needs 373 , 410 is to much as i do highway the truck on occansion. 410 is great if you want to no milage . whatever you do make sure you recalibrate the psom!

 

What makes you guys think 4.10's will kill milage, with 32" rubber rpms are only 2150@70mph, and only 2200rpm with 31" tires. Considering it'll take less throttle input to maintain speed with the higher mechanical advantage the gearing provides, milage may actually increase. Of course, if you just GOT to drive 85mph while towing then there's no hope.....

Curtis.. have you actually measured the milage you get with that truck? There's not a snowballs chance in hell it gets anything better than 12 city and 15 hwy.

 

I think you're wasting your money, but it's your money and your truck.

 

Well considering mines obd-II sefi-ma not speed density batchfire mines even got a crank position sensor its not like most 351s and I take it easy it does it, get on it yeah it goes down way down. The first 10k miles I had the truck i was writing down the mileage in the log book and keeping track of it, heres from when I went up north in Michigan with a ton of crap towing it went 302mi. on front tank put in 14.361gal. on June 1 around town here from last week 286mi. on the rear tank put 17.161gal. in am I still wrong? As for 4.10s and this truck I know its not a huge increase in rpm but still like the idea of a 3.73 the best with it not being too high but not a 3.55 its when you have no OD is when they really affect you. As for right now I am just throwing the idea out there, I have to get my 400 into the 92 done before I worry about gears.