Does the ud pulleys make a real diff or sotp diff?

 

City mileage seems to be close to the same or a little better, but honestly I can't keep from racing it around long enough to give you an accurate answer. I am pulling a small enclosed trailer about 500 miles this weekend so I will see how it does mileage wise there and let you know.

With a 32" tire (35/50R20) my truck is at the following speed/rpms cruising on the highway in 6th gear.

65 - 2050ish
70 - 2200ish
75 - 2350ish

 

It sounds as if you’ve got a good plan for your current set-up and by using your past experience you’ve already have a jump start on most as to what’s needed.

Keeping your current 5.3L I would go with a set of 1.75” long-tubes, but the Doug Thorley’s should still work nicely with your stock exhaust system, without having to worry about changing cat placement or really increasing the decibel levels much. I too wouldn’t worry about changing the cat-back unless your just after a better tone, however if this truck is going to spend a good deal of time burning up the highway’s loaded, you may not want to listen to rumbling (resonance) all the time. I really believe the 4.10’s will be a nice improvement for towing larger loads – 1st will become more of a Granny Gear and 5th and 6th will become more useable. No doubt whatever changes you make, I know you’re going to get it tuned, so that goes without saying. As far as going with forced induction and towing, I would not be concerned with ill effects from it. You could greatly benefit from the additional torque output, as it will be at all ranges, not just low-end and will keep things in the meat of the power without having to downshift all the time. While I would choose a roots style for the instant power, there is nothing to say that a turbo wouldn’t do wonders, just whatever system you went with, I would go with a 2-Bar Map and an EGT gauge to monitor exhaust temps. The 2-Bar Map should help return a very slight improvement in fuel economy under partial boost and by monitoring the EGT’s you will know when things are getting out of hand and you need to back out it. Also, while I whole heartedly believe the 4.10’s will show you the improvements your after when towing, by being boosted as well you should find all the towing improvements you should need without resorting to an even lower gear ratio, which should keep things nice when cruising down the highway unloaded as well.

 

What about performance?

 

Great info on the rpm , Thanks thats about 150 rpm higher than the calc gave me ...........but thats even better .......... mileage yes I saw same thing in city ....overall going to 4 10 does not hurt much if any until you drive faster than approx 65


Thanks

 

For sure the 4.10's are a go .....knew I needed a gear change was just not sure what # with that 6spd ...........now I know
I hear you about the boosted deal .never know may do that ........ the DT Thorleys are the long tube model ......and they wont bolt up to the stock cats and your right with stock single exhaust system with just a 3" Magnaflow there is a drone towing .....thats whats on my 04

I am goin to be stubborn and stick to the smaller tube / collecter TriY header I really beleive they will move the torque band down lower compared to a 4 tube header .too bad I never dyno'd the 04 after the headers I am sure someone on here has dyno for the 4 tubes on a stock motor ....... the problem is most dyno only start to measure from about 3500 and up ...........and for towing you need more torque down lower

 

And that's supposed to be a 305/50R20, didn't notice my typo until just now.


@ ssierra08, the sotp pants meter is very noticeable going from the 3.42s to the 4.10s, I will have be taking it back to the track in the next few weeks to see the improvements from the gears before I install my 3200 converter.

 

so you want more torque go the way im going 408 stroker !!! lol

 

Okay man I got some data for you, your towing trailer and weight will be different I'm sure, but this is real world data from today.

I towed a 6'x12' enclosed trailer a little over 450 miles today so I thought it would be nice to collect some information for you and anyone else who may be interested.

Trailer Size
6' wide x 12' long and the top of the trailer was around 7' tall.


Trailer Weight
3000 total trailer and load weight. The trailer was 1920 lbs empty so I am saying that the load was at least a 1000 lbs .


Fuel Economy
Averaged 14.1 mpg @ 65 in 6th gear around 2100 rpms cruising and it would go up to 2350 pulling some hills, but never down shifted to 5th.

Averaged 13.4 mpg @ 70 in 6th gear around 2250 rpms cruising and it would go up to 2400 pulling some hills, but never down shifted to 5th.

Averaged 12.8 mpg @ 75 in 6th gear around 2400 rpms cruising and it would go up to 2550 pulling some hills, transmission downshifted into 5th a couple of times pulling hills. (Went up to 2900ish rpms when it was in 5th gear for a few seconds pulling these couple of hills.)


Transmission Temperature
It was 60 to 65 degrees outside during my trip.

At 65 mph the transmission temp mostly stayed around 178 degrees and reached a high of 180 degrees.
At 70 mph the transmission temp mostly stayed around 182 degrees and reached a high of 184 degrees.
At 75 mph the transmission temp mostly stayed around 186 degrees and reached a high of 190 degrees.

This data was collected doing a couple of 50 mile sections of the trip at each of the different speeds and the cruise control was set to let the truck maintain the set speeds.

 

Great Info , Thank-you for doing that ......seems like the 4.10's work great with the 6spd and your mileage is excellent .IMO .....My trailer is a 22' 7000lbs loaded ...your info tells me I will be able to cruise in 5th no problem yet not be reving too high .......that is fine with me if I can average 10mpg that would be great too