i have a 95 ram, i am getting a set of 38" or 40" tires for it. what gears do i need to put in it? it is a DD and mud boggin truck. its running 35"s on stock gears. what gears would best pull the 38" or 40"? and also, i am thinking about getting a throttle body spacer, whats the best kind to get for a 5.2L. and does it have a good advantage over stock or not that much difference? thanks in advice for any help.

 

First of all, throttle body spacers are JUNK.

Second of all, you'll need a lift kit to clear 38s....and obviously 40s.

Thirdly, you're going to HATE your mileage if you're going to use that large of a tire on a daily driver. You're also going to HATE having to replace the tires every 10,000-15,000 miles...because mud tires do NOT wear (or ride) well on the road.

As for gear ratio, you'll have to go to at least 4.88s to turn the 38s, and probably higher to turn the 40s which will get costly as you have to switch carriers. The stock carrier is only good for 4.56s if I remember right.

Not to mention the 318 you have will be VERY underpowered with that large of tire...and it will put CRAZY amounts of stress on your axles, especially if you plan on actually taking it off-road.

Not a good idea all around in my opinion. If you want to build a bogging truck, trade up to a 3/4 ton with a 5.9 (360) and go from there. Doing it with a 318 powered half-ton is just asking for trouble [&:]

 

I agree with the throttle body spacers being junk.
As far as the gears go, you will already need a new carrier up front no matter what. The Dana 44 only holds 3.92. The Chrysler 9.25 can go up to 4.88. This would be perfect for the 38's. The 40's will need something bigger, and you'll have to buy a new carrier for the rear too. The gears are what keep your engine from straining so much. If you put the right gears in, you won't be able to tell at all by listening to the motor. What you do by putting bigger tires on is make the gear ratio longer, or make the number shorter. When you put a higher number gear in there, it shortens the gear ratio back to stock with the right gears so you can get the same gas mileage and speed as stock.

 

what is a carrier? i have already got it lifted. its lifted 3 inch body 5 inch susp. i dont know what a carrier is though? thanks yall!

 

I agree with some of what you're saying, but you will still notice a loss of mileage and power with as large of tires as he wants to run. It's not so much the gear ratio, but the added MASS of the tires and the rolling resistance that larger tires (especially mud tires) posses....not to mention the added stress on the drivetrain. The loss will be a lot less with a gear change, but it will still be there.

And a carrier is what the ring gear is attached to, and what holds the planetary gears.

 

TB spacers are junk on these motors, but I would recommend a rebuilt performance TB with larger holes. They actually do alot for the motor and are very easy to install. The one I bought for mine was pretty easy on the pocket book as well.

 

4.88s are not enough to turn those 40s. you would get by with 4.88s with 38s. But you have no choice because the 4.88s are the higest you can go with the 9.25 rear end.


You can get away with running thinck gears in the D44 without getting a new carrier.
I had 4.56s with 35s and wanted to go to 4.88s. I couldnt imagine having 38s and 4.88s.

If you have a standard tranny you would be fine but an auto will dog like no tomorrow


Do what burning rom said cowboy up for a 2500HD with a 360 and then lift it.

also, 8 inches of lift will make them 38s rub. unless you drive to the mall

 

With a 360, I might say 4,88's, but a 318?
I would run 5.13's.
DO NOT PUT 40's ON A 44! Not only will it break, but it wont stop either.
I run 35's, with 4.88's on my ramcharger, and love it, with the OD, it is perfect.
If you want a power increase, trade your intake in on a hughes, withthe filled in plenum.
Mileage will be in the 7's, with 40's.