Author Topic: th350/np203 to sm465/np205 conversion  (Read 4129 times)

Offline werewolfx13

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th350/np203 to sm465/np205 conversion
« on: March 22, 2015, 01:07:48 AM »
Still have my 76 k20 apart after trashing my TH350 a second time, and while I was looking for a solid case at a local salvage yard, the owner pointed out a 79 k10 that he drove in, lots of misc new parts on the truck, only reason they sold him the truck is severely worn valve seals, has an SM465/np205... He's willing to sell me both driveshafts, transmission, transfer case, pedal assembly, and all the linkages necessary, for a very reasonable price. Going to be swapping in my tbi 350 out of an 87 v20 at the same time. Do I need to swap the front end to manual hubs from the slugs immediately, or is it going to be alright to leave them alone for now? Should I run a flywheel for an 87 v20, and clutch set for a 79, or both for a 79? Figured I'd install a new clutch set and flywheel, switch to synthetic fluids, replace the seals, u joints, and such during the swap. Any bearings in either the transmission or transfer case I should be looking at replacing as preventative maintenance?

Thanks

Chris
'83 Chevy c10 Silverado SWB
'76 Chevy k20 LWB 6.5'x8' Flatbed
“I know that you believe you understand what you think I said, but I'm not sure you realize that what you heard is not what I meant.”

Offline Captkaos

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Re: th350/np203 to sm465/np205 conversion
« Reply #1 on: March 22, 2015, 12:36:46 PM »
You need the flywheel for the 87, the rest could be from either year as that was an optional trans.  Just make sure what you buy matches the spline counts on the input shaft.

Offline werewolfx13

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Re: th350/np203 to sm465/np205 conversion
« Reply #2 on: March 24, 2015, 03:29:24 AM »
Thanks, any thoughts on the hubs?
Chris
'83 Chevy c10 Silverado SWB
'76 Chevy k20 LWB 6.5'x8' Flatbed
“I know that you believe you understand what you think I said, but I'm not sure you realize that what you heard is not what I meant.”

Offline Captkaos

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Re: th350/np203 to sm465/np205 conversion
« Reply #3 on: March 24, 2015, 12:23:35 PM »
I would want the unlocking hubs on a 205, you won't be able to drive it on the road as it doesn't have the differential the fulltime 203 has...

Offline werewolfx13

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Re: th350/np203 to sm465/np205 conversion
« Reply #4 on: March 25, 2015, 11:42:02 AM »
Thanks.
Chris
'83 Chevy c10 Silverado SWB
'76 Chevy k20 LWB 6.5'x8' Flatbed
“I know that you believe you understand what you think I said, but I'm not sure you realize that what you heard is not what I meant.”

Offline DustyRusty

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Re: th350/np203 to sm465/np205 conversion
« Reply #5 on: March 26, 2015, 08:09:12 PM »
Do I need to swap the front end to manual hubs from the slugs immediately, or is it going to be alright to leave them alone for now?

You can leave the slugs in for now but make sure your 205 t/c is in 2wd on hard surfaces.  With the slugs your hubs are permanently "locked in".  When you need 4wd all you need to do is shift the t/c into 4wd. 

The owner's or service manual actually suggests locking in the hubs on 205 t/c equipped vehicles for a number of miles while in 2wd to lubricate the gears in the differential.  But eventually you should probably consider installing the unlocking hubs.

Rusty
1975 K-10 SWB Fleetside - 350/SM465/NP205/D44F 12-boltR, 3.73 gears.  Original owner.
Customized by rust.