Author Topic: NP203 Part Time Conversion Kit  (Read 15647 times)

Offline blast

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NP203 Part Time Conversion Kit
« on: May 06, 2008, 02:33:44 PM »
I just ordered up the Mile Marker part time conversion shaft for my np203.  The shaft replacement one.



Should be here Thursday, just wondering if anyone had any experience or "gotchas" I should be worried about during the install.

Really looking forward to getting this installed.  ;D

Offline blast

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Re: NP203 Part Time Conversion Kit
« Reply #1 on: May 14, 2008, 05:52:46 PM »
Follow up:

Installed today.  Very easy install (1.5 hours), even though Mile Marker's instructions are vague and didn't really cover my model.

Working great.  I heard my front tires say "ahhhhhhhh!"   As far as mileage improvement, we'll see, I have a feeling the 454 will say "whatever dude".


Offline Fordeatinz71

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Re: NP203 Part Time Conversion Kit
« Reply #2 on: May 15, 2008, 12:39:23 AM »
sweet man!  this info comes in handy as i have a deal in the works to possibly trade the Sierra for a '78 Jimmy...although i may just throw a 205 in it...
1991 Chevy Silverado K1500 ECSB, 350, 700R4 w/shift kit, 3.42's, exhaust work...
1983 GMC Sierra K1500 SWB-sold :(

Offline blast

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Re: NP203 Part Time Conversion Kit
« Reply #3 on: May 15, 2008, 11:23:42 AM »
Here's a couple links to better instructions:

http://coloradok5.com/milemarkerpt.shtml
http://www.4wheeloffroad.com/howto/47538/index.html

My NP203 had a metal oil pump, it is pressed onto the existing shaft that is replaced by the Mile Marker shaft.  I could not find the plastic oil pump gear replacement for the NP203 GM PN 11801, apparently it's discontinued, so I had to unpress the metal gear from the old shaft and press it onto the new shaft.

Also, the torrington bearings and accompanying thrust washers were not mentioned once in the Mile Marker instructions, depending on which shaft Mile Marker sent, you may or may not have to install these.  Here's a pic to help decide if needed or not, these were given to me later by someone at Mile Marker, would have been nice if they were in the kit to begin with.