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Discussion Starter · #1 ·
Question:
I have a stock 400 in a 75' TD, 727 Auto, Dana 44HD/Dana 60 with 4.10 gears running 44" Super Swampers. The TD runs well enough but just seems like it runs out of power.The 400 has a very hard time turning the tires when in some thick mud. Otherwise it runs well. I do have a 440 but it smokes really bad.Any suggestions where to start? I am on a limited budget as well. Have to do a little at a time.
 

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not enuf gear for the 44,s / with 4:10,s you should only be running 35 or 36 inch tires / for the 44,s you need 4:88,s or 5:13,s / but l think the dana 44 gears only go as high as 4:88
 

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Yeah I agree, you need more gear. A stock 400 isn't strong enough to turn the 44's with ease. A stock 440, maybe. I had 4.56 gears with my 40x17 ground hawgs and a 440 in my old RC, and as know from the pics it could do burnouts on the street.

4.10 just isn't enough. I am going to 5.13's here shortly. Skip, something that might help is if you trade me those 44's for the 4 38x15.5 swamper and 4 36x12.5 hummer tires I have :) I also have 38 and 36" spare tires :)
 

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Discussion Starter · #4 ·
I know three people running the same set up except with stock chebbys, one a 350 and the others are 454's. They have no trouble turning the tires with those gears. Going down in tire size might not be the option I'm looking for. If the 400 won't do then I'll get something else. I may change diffs as well.
 

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Skip are you running in 4 high or 4 low ? If your running in 4 high then i would say go with low. i usually run in 4 low when im wheeling. i iwll agree though that lower gears will make the difference, even i want lower gears and i only have 36' tires. But if your looking to just throw the 440 in to replace the 400 then go for it. But im pretty sure you are going to be breaking drive shaft and axles just for the fact that haveing such high gears and big tires will out alot of stress on the joints. If you don't want to get lower gears then getting smaller tires will help. And yet another option is to take the 440 crank out of your 440 and put it in your 400 and make a 451 stroker like brad's. but if you went with rockwells those 6.72 gears will make a world of difference you will think that you have anew engine in that thing from the power youll get from lower gears. just a few ideas and my .02 :)
 

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You could advance the cam to bring the powerband rpm's down further. I.E. Maybe the way you currently have the 400 set up it doesn't have the low-end 'grunt' it needs. The trade off here is while you gain low-end, you lose top end....

Otherwise I would tend to agree with the others...turning 44's with 4.10 gears is asking a lot of your engine IMO (this equates to around a 3.21 effective gear ratio assuming those 44's are 40" actual diameter--even lower if the tire is taller than 40")

What is the stall speed of your torque converter? If it is stock that is likely killing your low-end more than anything else.

-SM
 

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Skip i'm in the same boat. I'm considering going to 404 MOG portals just so I don't have to get new gears put in my 60's. I need driveshafts made anyways, so maybe portals are my solution.
 

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Discussion Starter · #8 ·
I have access to some older closed knuckle diffs that I may try. They are 5.86 geared. I may have to play with the timing some as well. Also thinking of changing the carb, plugs, and wires. Also have a MSD 6AL box. Just got to figure out what I can get done.
 

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Toyradio said:
I have access to some older closed knuckle diffs that I may try. They are 5.86 geared. I may have to play with the timing some as well. Also thinking of changing the carb, plugs, and wires. Also have a MSD 6AL box. Just got to figure out what I can get done.
Well the gears will help alot, have you ever replace the timing chain? that will help if your has slack in it
 

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Discussion Starter · #10 ·
Its a stock 400 aint done squat to it but change the plugs and oil.
 

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well, a higher stall speed on the torque convertor will help, but it will hurt you mpg some.
 

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Discussion Starter · #12 ·
Don't care about the mpg. It's an off road only rig. Need more low end hp and torque. We never go over about 10 mph or so.
 

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Discussion Starter · #14 ·
We haven't ruled out going to smaller tires............. not exactly sure yet what we will do. Trying to solve the horse power issue right now.
 
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