Gas Milage with the 3.7L suchs really bad. I am in the proccess of building a self contained detailing rig. I am going to have to haul around 70 gallons of water everyday. Here is my question to everyone.

Should I get a 4.7L HO and if so will I be able to use my tranny.

OR

Should I swap in an LSx 5.3L into the truck. One of the shops I work for has 10 brand new 5.3 LSx motors that he got from chevy. All the motors have 0 driving miles on them. They were used by chevy as dyno motors. Every so often a motor is pulled off the line and runs on the dyno to make sure it is peroforming the way it is suppose to then they sell the motors.

Also should I swap my 3.55 rear gears for the 3.90 gears

Im not going to swap out my rear end because I am just going to be running basic bolt on and a tune so my rear end should be fine

 

if the 3.7 uses the 45rfe trans then you can swap. not sure if it does though. gears would probably help a ton too.

 

Chevy in a Dodge? That would be interesting.

 

Do you have the 9.25" rear end right now? If so, buy Blown's 4:10's and your current engine set up should be fine. You are looking at about 585lbs of water, plus the container; I would just do an add-a-leaf to support the added weight, along with a higher gear ratio, and see how it runs.

 

I agree completely, sorry mine sold yesterday to a G3 Ram guy on DT.

 

what did i miss?

 

You know I grenaded the "C" clips in my stock LSD. About a month ago the clutch packs shot out the spring retaining clips and seized my rear end solid. The stock LSD is trashed but I was able to save the 4.10 Ring and Pinion.
https://dodgeforum.com/forum/3rd-gen...y-oem-lsd.html

 

the 3.7 should have enough ***** to do what you want just change the gears and put an add a leaf and new heavy duty shocks on and you should be fine. you might want to make sure you have a little rake in the truck so when you tow you tow level

 

I want better gas mileage and more power. The rear gear will be able to handle the 5.3L one of the shops I work out of swapped a 5.3L into a 2005 Jeep Wrangler and kept the stop rear end and it smaller then our trucks. I have 2 friends that own 2 different shop both are chevy guys.

If I swap the 4.7L in I would need the motor a 4.7L ecu and new tranny.
If I get the 5.3L LSx I would need the same thing but can get a motor with no miles on it for about 1k and have my friend tune it with HP tuners for free since I am doing IT and Detailing work for there shop.

What would you guys do and what do you think would be more badass and get me the best mpg