TH350 & NP203 to NP205? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Redcap · 06-07-2010, 02:49 PM

I have a TH350 married to a NP203 that has been used pretty hard and I don't trust it at all. I'd like to replace it with a NP205 and have access to one off of a TH350 (and adapter), but I'm curious to know if this is a direct swap or if driveshafts will need to be shortened/lengthened or if there are any other snags with this swap?

Thanks!

70 beast · 06-07-2010, 07:13 PM

there will be drive shaft alterations but otherwise its a bolt n go swap.

**MacSic66** · 06-07-2010, 11:55 PM

Quote:

Originally Posted by 70 beast

there will be drive shaft alterations but otherwise its a bolt n go swap.

agreed! i did it in my 75, bolt on, moved the t-case crossmember to the next set of holes, driveshafts will have to be adjusted, shifter comes up in the same hole even..

84 400 · 06-11-2010, 08:34 PM

Just did it this past winter
Truck was a 1977 k10 Short bed. THERE IS NO NEED TO MOVE THE TRANSMISSION CORSSMember If using a th350!! in a truck that had a th350!

You need to lengthen the rear drive shaft and get a shorter front shaft. On the front shaft you can get a drrive shaft out of a truck optioned with a sm465np205 witch is the shortest shaft out there and get a longer slip yoke. I have the part number if needed. Or you can cut down the np203 front drive shaft. You will also need the 4 bolts to attach the adapter to the transmission in which the top two need to be longer then the bottom two. I would also do new mounts.

Also double check that both use 27 spline? input and out put shafts. There are a few odd balls with 30splines?

06-07-2010, 02:49 PM	#1
Redcap Registered User Join Date: May 2010 Location: Lewis County, WA Posts: 1,523	TH350 & NP203 to NP205? I have a TH350 married to a NP203 that has been used pretty hard and I don't trust it at all. I'd like to replace it with a NP205 and have access to one off of a TH350 (and adapter), but I'm curious to know if this is a direct swap or if driveshafts will need to be shortened/lengthened or if there are any other snags with this swap? Thanks!

06-07-2010, 07:13 PM	#2
70 beast Certified Hobbiest Join Date: Jul 2007 Location: Sacramento, Ca Posts: 384	Re: TH350 & NP203 to NP205? there will be drive shaft alterations but otherwise its a bolt n go swap. __________________ my jimmy build http://67-72chevytrucks.com/vboard/s...d.php?t=352536

06-11-2010, 08:34 PM	#4
84 400 Sb 400 club Join Date: Nov 2005 Location: NH / MA Posts: 2,741	Re: TH350 & NP203 to NP205? Just did it this past winter Truck was a 1977 k10 Short bed. THERE IS NO NEED TO MOVE THE TRANSMISSION CORSSMember If using a th350!! in a truck that had a th350! You need to lengthen the rear drive shaft and get a shorter front shaft. On the front shaft you can get a drrive shaft out of a truck optioned with a sm465np205 witch is the shortest shaft out there and get a longer slip yoke. I have the part number if needed. Or you can cut down the np203 front drive shaft. You will also need the 4 bolts to attach the adapter to the transmission in which the top two need to be longer then the bottom two. I would also do new mounts. Also double check that both use 27 spline? input and out put shafts. There are a few odd balls with 30splines? __________________ 1984 chevy c10, built 400sb,.(SOLD) 77 K10 Project / daily driver "The Grinch" http://67-72chevytrucks.com/vboard/s...d.php?t=318363 1956 Willys Wagon (327 chevy) Project (Now Buick 225) 1980 Corvette L-48 4 speed 1992 Mustang GT built 5.0 5 speed 1985 C10 LWB Sold 1982 K10 SWB plow truck Parted out 1986 D30 M1028 fire brush truck Parted out Last edited by 84 400; 06-11-2010 at 08:37 PM.



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