Which Transmission?

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paulrowe

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My truck currently has a TH350 with an NP203. The trans is leaking pretty bad and I'm sure could use a rebuild. I found a NP205 with a TH350 adapter for $200 today I was considering picking up. I also have a TH400 2wd trans that needs rebuild. Do you guys think the TH350 and NP205 will be ok for some light off road use and towing around 5000lbs? Or should I build the Th400 and collect all the pieces. I would need an adapter and to change the output shaft and new input on the tcase im assuming. It seems like getting everything to do the 400 will cost me quite a bit and I'm on a bit of a budget. So I guess I asking if I should use the th350 or go with the 400? I know the 400 is better but I wanted to save some $$$. I just don't want to put it all together and have to redo it all over in a year.
 
bucket

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I'd use the th350.

Getting the 205 setup for the th400 is expensive. You need the adapter, the input, the larger bearing to match and the case also needs machined to accept the larger bearing.
 
paulrowe

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That's the way I was leaning. I also have found a guy selling a th400 and 205 with drive shafts for $400. But he doesn't have the adapter either. But it all was mated at one point. Does this seem reasonable? I going to have to change driveshaft lengths when I swap the 205 in right? How much is a new th400 adapter? I only see them for 600 bucks.
 
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paulrowe said:
That's the way I was leaning. I also have found a guy selling a th400 and 205 with drive shafts for $400. But he doesn't have the adapter either. But it all was mated at one point. Does this seem reasonable? I going to have to change driveshaft lengths when I swap the 205 in right? How much is a new th400 adapter? I only see them for 600 bucks.
Click to expand...

Seems fair compared to what I put into mine. Is it a known working trans from an honest fella though? If not, plan on a rebuild if there's any doubt.

I thought new adapters were less than $300.
 
paulrowe

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No I have no idea of the condition. I planned on rebuilding either one. I guess it might be better to use what I have. Do you happen to know what drive shaft modifications I'll have to do?
 
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I don't know, when going from a th350/203 to a th400/205.
 
HotRodPC

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Th350 is plenty strong for moderate wheeling and towing 5000lbs. Towing that much though, I'd add an additional aux cooler. DO NOT bypass the OEM radiator cooler, keep it too AND add the aux cooler. I actually prefer a Th350 over a Th400 if I don't need the brute strength of a Th400. Th350's have a better attitude IMO becuase you can tune the way you want them to shift, where as a Th400 you only get a governor and vac modulator. You get that, Plus the detent cable to the throttle linkage, so you can actually tune the shift points to where you want them much easier as well as shift kickdown, where on a Th400 you pretty much have to floor board it to hit the kickdown switch.

If you're rebuilding the TH350, I'd upgrade the outer race on the intermediate roller clutch/sprag to a hardened one, and not some POS China claimed to be hardened from China.
 
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Ooh a 27 spline 205... hard to find out west. Everybody was ordering 4 speeds back then. I like those 27 spline 205s... behind a decent 700.
I would but that tc from in a pinch... if you weren't 3000ks east.

Your 350 I agree with the guys will be fine for some light towing. Get a good tranny cooler installed and a Transgo shift kit. You don;t want the tranny slipping between shift. Bang get it over with.
 
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shiftpro said:
Ooh a 27 spline 205... hard to find out west. Everybody was ordering 4 speeds back then. I like those 27 spline 205s... behind a decent 700.
I would but that tc from in a pinch... if you weren't 3000ks east.

Your 350 I agree with the guys will be fine for some light towing. Get a good tranny cooler installed and a Transgo shift kit. You don;t want the tranny slipping between shift. Bang get it over with.
Click to expand...
I'd go with the Stage 1 RV Shift Kit. Firm and Positive shifts. Stage 2 is a bit hard and you don't really care to have the transmission beating on the transfer case input, not that a NP205 can't take it, but in general Stage 1 RV kit is perfect for 4x4's and on the chain driven type, you're not beating on the chain either trying to stretch it out.
 
shiftpro

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HotRodPC said:
I'd go with the Stage 1 RV Shift Kit. Firm and Positive shifts. Stage 2 is a bit hard and you don't really care to have the transmission beating on the transfer case input, not that a NP205 can't take it, but in general Stage 1 RV kit is perfect for 4x4's and on the chain driven type, you're not beating on the chain either trying to stretch it out.
Click to expand...
HRod what would you recommend for a 4l80 with 205 behind say.. 500 fptorque? This is the setup I'm setting up for my 496. Thanks.
 
HotRodPC

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The Np205 can probably handle the abuse or a hard shift and no chain to stretch so if you really want that neck snapping shift you could do it. I don't have alot of experience with the 4L80-E, I did a clutch and seal freshen up on 1 with new solenoids and that's about it. I've not experiemented with any of them as far as shift quality mods and aftermarket kits.
 
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shiftpro said:
HRod what would you recommend for a 4l80 with 205 behind say.. 500 fptorque? This is the setup I'm setting up for my 496. Thanks.
Click to expand...

4l80e and a 205 is the same setup im going with. only i plan on running a 6.0 LS. The 496 should make some good power, i had one in my chevelle and it made right at 500 hp and 650 tq on pump gas.
 
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