Author Topic: Installing TH350 & NP203 question  (Read 8188 times)

Offline Dirka

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Installing TH350 & NP203 question
« on: September 30, 2014, 06:11:49 PM »
Same topic different question.
I have my 400sbc, TH350 and NP203 all out of the truck, they've all either been cleaned or rebuilt and now are ready to be put back under the truck.
My question is what should go in first? Engine, then tranny, then transfer? Put tranny and transfer case together then put up as a unit and button up all the drivetrains and then the engine?
Also should I have another rear support bracket under the truck to hold up the rear end of transfer case? I only have one that bolts up to where the tranny and transfer case mount together.

Offline Jason S

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Re: Installing TH350 & NP203 question
« Reply #1 on: October 03, 2014, 10:58:42 AM »
Is the front sheet metal off the truck?  If so, then I'd consider installing at least the engine and transmission together. 

Otherwise, I'm thinking set engine in place and use a transmission jack to mount the transmission and transfer case. Mounting can be either seperate or together. That NP203, as you're probably aware, is heavy and can be dangerous when working under a truck. Strapping it to a proper jack can save you a lot of hassle. After Engine/Transmission/T-case are installed and bolted down,  then button up driveline.

The one mount under the transmission to transfer case adapter is the minimum that's needed. Although there are t-case to engine struts and frame to t-case brackets that were used to beef up the mounting.
1973 GMC K2500, Super Custom, Camper Special, 350, TH350, NP203, 4.10's
1974 Chevrolet K10, Custom Deluxe, 350, SM465, NP203, 3.73's

"1) Peace through strength; 2) Trust but verify; 3) Beware of evil in the modern world"

Offline Dirka

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Re: Installing TH350 & NP203 question
« Reply #2 on: October 09, 2014, 07:50:27 PM »
Just an update on how things are going back in!
I ended up matting the tranny to the transfer case and installing the mounts and crossmember all as one piece and then stuck it up under the truck.  It went really well! Just two of us and two jacks =)

Offline Jason S

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Re: Installing TH350 & NP203 question
« Reply #3 on: October 10, 2014, 09:49:21 AM »
Great job, very clean! 

Extra help can make things go so much easier, it's something that I rarely have.

Can't wait to see photos of the engine installed.
1973 GMC K2500, Super Custom, Camper Special, 350, TH350, NP203, 4.10's
1974 Chevrolet K10, Custom Deluxe, 350, SM465, NP203, 3.73's

"1) Peace through strength; 2) Trust but verify; 3) Beware of evil in the modern world"

Offline Dirka

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Re: Installing TH350 & NP203 question
« Reply #4 on: October 11, 2014, 11:09:42 AM »
Can't wait to see photos of the engine installed.

This is something that's not going very well! It shouldn't be this difficult, but things are not lining up!
Mounting brackets and holes in frame are off by about an inch maybe more.  Have it lined up and pre bolted up to the transmission, and it looks like the engine is sitting too far back (toward the firewall) from where it was before.
I went from a 305 to a 400 and used the brackets off the 305.

Offline Captkaos

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Re: Installing TH350 & NP203 question
« Reply #5 on: October 14, 2014, 09:17:27 PM »
SBC are the same length so the bore/stroke size has nothing to do with it. 
this is the same transmissions right?  Is the trans still bolted down?  I have the trans free from the mount when I am hooking them up.

Offline roundhouse

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Re: Installing TH350 & NP203 question
« Reply #6 on: October 14, 2014, 10:01:42 PM »
If you ever have to pull the trans

Get some long  lots and cut the heads off. Screw em in the back of the engine and that will help line it up

Offline Dirka

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Re: Installing TH350 & NP203 question
« Reply #7 on: October 15, 2014, 10:44:59 PM »
Update: 
Finally got the engine back in.  Come to find out I was using the wrong brackets (that attach to the block) cleaned up the spare set and the motor dropped right in with minimal effort!
Still waiting on my radiator and electric fan combo and then some help with the wiring of everything (single wire alternator, MSD Blaster 2 Coil, tachometer) that i've never done before.
Then I have some interior work to do!
 

Offline Jason S

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Re: Installing TH350 & NP203 question
« Reply #8 on: October 15, 2014, 10:48:41 PM »
Nice 400! 

Glad to see a good update.
1973 GMC K2500, Super Custom, Camper Special, 350, TH350, NP203, 4.10's
1974 Chevrolet K10, Custom Deluxe, 350, SM465, NP203, 3.73's

"1) Peace through strength; 2) Trust but verify; 3) Beware of evil in the modern world"

Offline Don5

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Re: Installing TH350 & NP203 question
« Reply #9 on: October 16, 2014, 12:40:42 AM »
Just an update on how things are going back in!
I ended up matting the tranny to the transfer case and installing the mounts and crossmember all as one piece and then stuck it up under the truck.  It went really well! Just two of us and two jacks =)

That's the way to do it! :) It looks good and I hope you post a video of it running.
It's been a LONG time since I have been called a newbie. Just sayin....

1979 GMC K15 355, SM 465, 205, 3.73 Dana 44 with a Spartan Locker, 12 bolt Eaton limited slip and 6 inch lift with 36 x 12.50 Super Swamper TSL's.

Offline Dirka

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Re: Installing TH350 & NP203 question
« Reply #10 on: October 30, 2014, 06:41:30 PM »
complete