2.8 cummins?, 302/5.0? ecoboost/4.0

[Smokes]

hey guys
i hope you can help.

i have a bronco ii that im planning a build for, and my dream-money-no-issue build is to do a 2.8t Cummins.
i think...

still open to the 302/5.0/ecoboost/4.0 options

im looking for good v8 power with great fuel economy and long time reliability. plus keep my 4wd

i have an offer to buy an tremec tko 500 which is ready for a 302/5.0. however my bronco ii is 4wd so i want to be sure i make the right decision. im also looking at the tremec tr 4050 that has a 4wd transfer case but i worry if it will put enough gunhoe to the wheels still.

what i want out of the build is
- for the truck to be quick. (but since its lifted i think "fast" will be dangerous and i dont want that.)
- to be able to handle daily driving very comfortably
- fuel economy to the max
- i want to keep 4wd. maybe convert to awd somhow?

i hope you all can help..

will this all boil down to my gear ratios?
can you tell me definitively that the tr 4050 or the tko 500 will work for my build?
any input on if engine selection will matter would be of help too.
this is assuming i can keep the money is no concern mentality.

 

[stmitch]

Can you define what you consider "quick" and what you consider "good fuel economy"?

Gearing is going to be critical no matter what, but "quick" and "good fuel economy" are kind of polar opposites in a lifted truck with big tires. You can gear it to be quick, but that's going to increase your rpms while cruising and reduce fuel economy. You can gear it to keep rpms low while cruising but that's going to make it a dog when you hit the accelerator.
Everything else being the same, I'd expect the Cummins would probably give you better fuel economy than anything else just by being a diesel, but it's going to prefer keeping the rpms lower to get there (peak torque @ 1800 rpm) so that's a tradeoff with gearing and quickness.

 

[Smokes]

I suppose what I mean by “quick not fast” is
I don’t need or want a high top speed (fast) really.
However when accelerating i want the peddle to have play in it where I CAN slowly accelerate but I can also give a bit more and take off.(quick)
I figure having a diesel will help with fuel economy.
but I do not know how to figure out my gearing.
I’m leaning towards a tremec 4050 or something in that family. That way I could install an AWD transfer case over 4x4 so I can have a nicer ride (in theory) on pavement and still go off-roading if I feel like trailing. If I comes to it I’ll settle on 4x4 but I won’t be heartbroken.
is there a formula to finding a good balance in my gearing Considering I’m putting a completely different engine and trans in?

 

[Curious Hound]

This chart might help you out some.

Gear Ratio & RPM Guide For Larger Tires - The Ranger Station

This Gear Ratio & RPM Guide will enable you to see how many RPM's your engine will turn based on gear ratio and tire size.

www.therangerstation.com

Find out what rpm Your engine should be operating at highway speed with the transmission in high gear (1:1 ratio). Use the chart to decide what ratio you want in the differential for the tire size you want to run. Then, if you want, choose whichever transmission will give you the right gearing for acceleration in the lower gears, keeping your engine in the right rpm band.