4.7l 2000rpms at 80mph

[adamh3844]

I have the 545rfe with 3.55 gear ratio in '02 4.7l quadcab 4x4 with 33" tires.
Running at that speed I get around 19mpg but I am concerned about bogging down the engine.
at 70mph I'm close to 1500rpms. Going up slights hills it generally doesn't shift out of OD.
Also have Superchips F5 and am planning on adding '08 intake amnifold and 70mm Throttle Body.
Would this increase my power to a point I would be okay to keep gear ratio or should I look into possible 4.10s?
Also I am on a slight budget so it would most likely be either Gear ratio change or intake change

 

[HemiLonestar]

You have the 45RFE, 2002 4.7 didn't get the extra OD gear. If you're at 1500rpm at 70 if you actually had a 545 your rpm would be even lower (like 1200 or so). Big heavy truck + baby 8 + tall tires = you need more gear/mechanical advantage. More bang for buck would be gear change, you'll gain a little bit of power with a manifold change (the bigger TB won't do you any good on a stock engine) but not the instant difference of a gear change. You should at least be running 3.92's with that setup.

 

[adamh3844]

I actually replaced the TCM in my truck with a Jeep GC TCM and it was immediate change in transmission feeling along with highway mileage.
Apparently the only difference of the 45rfe and 545rfe are the programming.
I do have a 4x4 would I be better off trying to find gears off a truck with 3.92's or should I look into just buying 4.10s?
Before the TCM change I sat about 500rpms higher on highway and truck constantly would shift in and out of gears for the slightest hills.
Also. if I don't feel the truck bucking or seems like its dying going up hills can I still be doing damage to engine?

 

[HemiLonestar]

I actually replaced the TCM in my truck with a Jeep GC TCM and it was immediate change in transmission feeling along with highway mileage.
Apparently the only difference of the 45rfe and 545rfe are the programming.
I do have a 4x4 would I be better off trying to find gears off a truck with 3.92's or should I look into just buying 4.10s?
Before the TCM change I sat about 500rpms higher on highway and truck constantly would shift in and out of gears for the slightest hills.
Also. if I don't feel the truck bucking or seems like its dying going up hills can I still be doing damage to engine?

Ahhh ok, you did the TCM mod, yes only difference on the two is programming. Well, it would probably cheaper to find 3.92 front and rear differentials from a similar year. You'd have to buy 4.10 gear sets for front and rear plus pay to have them both setup properly, unless you have the tools and know how to do it yourself. Mine is 2wd but I have 4.56's I put in (I cheated and swapped rears though lol). Awesome acceleration and better for towing, the trade off being highway mileage.

 

[mwclarksr]

Mine is 2wd but I have 4.56's I put in (I cheated and swapped rears though lol). Awesome acceleration and better for towing, the trade off being highway mileage.

I'd say so, on the trade off. Why did you get those tall gears, are you doing 1/4 mile racing with your truck?

 

[HemiLonestar]

I'd say so, on the trade off. Why did you get those tall gears, are you doing 1/4 mile racing with your truck?

Short gears lol. Tall gears are numerically low, shirt gears are numerically high. I wanted better towing ability, better acceleration and my original 9.25" was on its way out. I had already swapped to SRT brakes up front; so I swapped in a Dana 60 from an SRT quad cab. 4.56's, LSD, matching brakes all in one and damn near a bolt in.

Sent from my HTC U11 using Tapatalk

 

[mwclarksr]

Well, if it works, it works. Take a peek at my swap thread, please. I had a question that you may have an answer to.

 

[SYKRAMMAN]

I actually replaced the TCM in my truck with a Jeep GC TCM

That was the single best thing I did to my truck! I used an 04 Jeep gc tcm. Instant results, no programming, no flashing, nothing but plug n play!

 

[adamh3844]

Ahhh ok, you did the TCM mod, yes only difference on the two is programming. Well, it would probably cheaper to find 3.92 front and rear differentials from a similar year. You'd have to buy 4.10 gear sets for front and rear plus pay to have them both setup properly, unless you have the tools and know how to do it yourself. Mine is 2wd but I have 4.56's I put in (I cheated and swapped rears though lol). Awesome acceleration and better for towing, the trade off being highway mileage.

Would you be able to point me in the right direction with some links
I see some that are master gear sets online and some that are just the gears.
And would I lose much highway mileage since I already sit so low in RPMS at 80. Wouldn't this even me out to get more power to wheels and bring me down to around 75mph at 2000rpms? and I also do a lot of city driving and I feel as though I have to give my truck extra to get it moving. Doesn't help that I have the 4.7 puppy but could the 4.10s possibly increase city driving since it will be more power to wheel. Also I run 33"s so I am somewhat out of the "Gear range" for that size tire apparently.
https://www.google.com/search?tbm=i...bkkEI#imgrc=AOrZRPriNsEUjM:&spf=1526561996758

 

[HemiLonestar]

Well, if it works, it works. Take a peek at my swap thread, please. I had a question that you may have an answer to.

Answered lol