350/7004r/203 "gearing"

toyotafreak

toyotafreak

they call me spaz
Joined
Nov 14, 2006
Location
China Grove/Mooresville
finally going to tons on my 87' toyota finally got my(60/14ff) and i just picked up 98' chevy ck1500 4x4.
So this is what i plan on trying to run
-vortec350/700r4/203
-5.38's
-plan to run 42's and ^
what kind of gearing am i looking at, is this going to be too low/ high... i have no idea all i kno is toy sht(22r/g54/duals = :driver:)
but since i'm going to an auto and V8 instead of a few rats under the hood....
do i need an atlas, another full size case ???
i need some full size wheelin guys to chime in here and tell me what i kinda need to do... thanks!:beer: :beer:
 
What did the T-case come out of? If it's from that 98 Chevy truck, it's not a 203.

If it is a 203, the low range ratio is 2:1.
 
I'll state the obvious.
203 is full time and relatively weak.
I would look for a 205 and use your 203 as a doubler, and honestly I have had more luck out of the 208s than 203s
 
As was stated, the low range on a 203 (2.0) sucks. The 5.38's and low 1st gear in the 700 R4 might make it half ass alright, but I have no personal experience to say. An NP208 or NP241 would give a better low range (2.6-2.8?), but are not the strongest TC's out there plus the Chevy versions have slip yokes. NP241's come in both driver and passenger side drop applications, so make sure you are getting what you need if you go that route. http://www.jbconversions.com/pages/ sells slip yoke conversions for the NP241 to eliminate that problem. You can use the output shaft and rear housing from Dodge NP208 on the Chevy NP208 to get a fixed yoke as another option of eliminating that problem. If you want to step up, go with a 203/205 doubler. Known to be pretty much bullet proof. Or, if you want to go all out, get the Atlas or Stak. You can also buy clocking rings for the NP208 and NP241 to make them flat. If you are interested in going with a 203/205 doubler, I'll post some links.

DK
 
I don't know how hard you beat on your junk, but a stock D300 would give you a nice overall ratio, and if you find a good deal on an Atlas, it'll then bolt right up.

I'm using a 205 on my 700R4, but I'm also running 6.72 gearing, which puts me in the same ballpark as yours with a D300.
 
i thought that a full time case is what came in the truck (98' 1500), but after searching it says that a 241/ or a 243 come in it... whats the difference. I guess i'll stay with whats in it if thats the case and just do a flat belly "3inch body lift on truck" and use the clocking ring... does this sound reasonable?
 
The 241 is a good case, I'm 90% sure it's a driver's drop case...

If you do run it, make sure you have a skid plate protecting it.. aluminum cases don't like rocks.
 
Is your D60 driver side drop or passenger? The factory TC(whatever it is) in that Chevy is going to be for a driver side drop front axle. I believe 98 saw a mid year change to the TC in the Chevy's. My 98 Hoe has the late year Autotrac TC or something. Don't remember what number it is.

DK
 
WEll it does not have a 700r4 it is a 4l60e and a np241

this is what I have in my truck. I am running 4.56 and 35's
 
4l60e= 700r4+electronic shift control module

Id rather have a 700 for cheapness but a 4l60 is an ok wheeler also.
 
SkyHiK5 said:
4l60e= 700r4+electronic shift control module
Id rather have a 700 for cheapness but a 4l60 is an ok wheeler also.
Click to expand...

I'd rather have the 4L60E because it will communicate better with the engine computer and you don't need the TV cable, but in THAT year, I believe it was the early tailhousing style, which was identical to the 700R.
 
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