Will a 205 hold up? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

feller · 11-03-2018, 02:35 PM

Just thinking about a possible future project, and I don't have any of the parts. But I am thinking about doing a k40, or k50 build (67-72 vintage) possibly (probably) a crew cab. My question is if I went duramax and either a zf6 or an allison, if I found a way to mate a 205 would it hold up? I would like it to remain passenger side drop and use as many Chevy parts as possible. Also would an nv4500 be a transmission option? Just thinking about this and am open to any ideas or advice.

Killer Bee · 11-03-2018, 04:28 PM

when I was entertaining a Dmax/Allison swap into a 71 K20, I found nothing on the shelf to hook up to an np205..

called several vendors, advanced, dirty laundry or something, diesel experts something, etc.. nothing allison to np205..

a saavy vendor down south recommended to look for later model mopar stuff, np 241 or something like that, also RH drop..

gal on the phone and her husband in the background spent at least 10 minutes giving me a laundry list of specifics..

still need adapters and speed sensor mod, etc.. couple of $k but at least doable..

I decided against it, not enough time for all of that, sounds like a good job for retired folks

here's the engine/trans I was looking at 07 LBZ Duramax 6 speed Allison

good luck!

eta: found my scratch paper..

Dave and K.C.
GM LAN
steering column shifter
tow/haul lockup
$2500 stand alone J1939
03-09 OE 4wd Allison tail housing, shaft, seal, bearing
Dodge motor mounts 89-93/95/98 lower profile
241 adapter $1300
OSS
shaft spline
RH drop early 90's Dodge 1500/2500 23 spline

feller · 11-03-2018, 08:56 PM

Sheesh!
Thanks for the info, it sounds like dodge or Ford axles, or a divorced transfer case would be better or cheaper. I guess it wouldn't matter and I would probably be the only one who knew. Another option might be a k4500 rollover and just do the frame swap I'd gain IFS from that

**Dieselwrencher** · 11-05-2018, 06:36 PM

You can get a 241d transfer case that was used in 86-93 gas 3/4 and 1 ton dodge trucks. This is a RH drop tcase and if you did do a NV4500 you can put the 29 spline input in it. I've heard of guys putting 208s behind allisons with upgraded guts so they can keep rh drop. If I was building a true K40 or K50 I'd be using non 8 lug stuff to stay true to it's rating but that is just me.

72 k15 · 11-05-2018, 07:38 PM

Dont know how to hook it up but, found a cool truck that you might want to take a look at basically the same thing with 2wd https://www.bismanonline.com/baker_m...dually_duramax

sweetk30 · 11-05-2018, 08:03 PM

these guys offer allision to np205 products and shifter cable brackets . https://precisionfabricationplus.com/

but there prices are CRAZY high . lots of there stuff is 2x the price / labor of offroad design stuff . but some stuff ord dosnt offer .

there is a guy on the other site that got there cable bracket kit . he was thinking there ally to 205 kit also but for the same basic money he went off road design MAGNUM BOX doubler . since the magnum box uses round 6 pattern it will bolt to about any trans easy . then the np205 bolts behind it with a new input gear that eliminates a coupler sleeve .

gets you 1:1 / 2:1 / 2.72:1 / 5.33:1 / TRUE 3 speed box .

http://offroaddesign.com/catalog/Magnum%20Box.htm

**71blksuper4x4** · 11-05-2018, 10:21 PM

A Dodge 29 spline from a First Gen cummins/getrag truck will bolt up, though I believe needs to be clocked.

I chose my LB7/Allison/29 spline np205 first with the GM D60. It would need a higher lift than I intended for my crew build. I wound up finding a Ford HP 78-79 D60 and Ford np205. I bought a kit with clocking ring and 29spline input to change the ford case. The ford D60 will help clear the offset oil pan, and get the truck lower to the ground.

1972K20 · 11-10-2018, 01:35 AM

Even if you get the NP205 mated up to the Allison, you still have to overcome the issue with the VSS to get it to play nice with the Allison TCM in 4low. Why not use a 2wd Allison and divorce mount the NP205? That way the VSS sensor can stay in the trans and there will be no issue. The 2005-2008 Kodiak's that where 4x4 I think that had a divorced transfer-case setup...not 100% sure though.

**Dieselwrencher** · 12-31-2018, 06:59 PM

Quote:

Originally Posted by 1972K20

Even if you get the NP205 mated up to the Allison, you still have to overcome the issue with the VSS to get it to play nice with the Allison TCM in 4low. Why not use a 2wd Allison and divorce mount the NP205? That way the VSS sensor can stay in the trans and there will be no issue. The 2005-2008 Kodiak's that where 4x4 I think that had a divorced transfer-case setup...not 100% sure though.

I'm pretty sure they did and I think they used NP 273s but I'm not 100% sure on that.

6BT 56 · 01-04-2019, 07:51 PM

Sounds like a cool build to me . I'd like to do similar. I'd like to build something 4500 or 5500 ish with a c50 cab and big fenders on it . I'm thinking f550 chassis. It's plenty tough . Has much bigger than 1 ton axles , 19.5 wheels etc. And junk blown up 6.0 superdutys are everywhere cheap. I'd like to do a cummins build. Motor mounts etc are easily available for that chassis and cummins drive lines are the proper side drop for that axle and t case . Koop us posted ��

74project · 01-06-2019, 04:08 PM

So what is the best trans/transfer case option for a cummins swap for a crew cab? So much info on this topic....

**Dieselwrencher** · 01-07-2019, 11:40 PM

I'm not sure there is a best really. Personal preference and parts availability has a lot to do with it. Just my .02.

**71blksuper4x4** · 01-08-2019, 07:42 AM

The Allison will hook up fine to the 29 spline np205, there are a couple adapters for the job on the market. You will need more lift on a GM Dana axle then Ford axle. The oil pan is offset to clear a driver side driveshaft. There is a guy who sells an aftermarket oil pan for clearance though. As far as getting past the 4 Lo/Reverse issue, you put the VSS in the tailsection of the Tranny and not in the tcase. Trevor

burnin oil · 01-09-2019, 12:19 AM

The Kodiak xfer case was a divorced mounted NP271. It is rare as hens teeth and the input parts are discontinued. I tried to find one about 5 years ago and gave up.

As far as transfer cases go the NP271/273 are stronger than a 205. They are beasts. My Dodge 5500 has been putting over 1000 ftlbs though one for the last 10 years. Truck is a G56 (6spd manual) with a dual clutch and factory 4.44s. Wieghs 12k empty and has grossed 36k for thousands of miles.

Alot of people talk down on the Dodge 241s also. My 95 2500 still has the original case (non HD so not the wider chain) at 320k and needed rebuilt, still does, when I bought it 100k miles ago. It is still kicking behind a 750 rear wheel HP 12 valve. The NV4500 was making death noises under boost so it got swapped for a G56. Ironically the NV4500 is now in my DD 72 K20 with a built 400SBC with no issues. I guess it was just to worn out for holding 1500 ftlbs of torque.

11-03-2018, 02:35 PM	#1
feller Registered User Join Date: Feb 2011 Location: madison, IN. Posts: 484	Will a 205 hold up? Just thinking about a possible future project, and I don't have any of the parts. But I am thinking about doing a k40, or k50 build (67-72 vintage) possibly (probably) a crew cab. My question is if I went duramax and either a zf6 or an allison, if I found a way to mate a 205 would it hold up? I would like it to remain passenger side drop and use as many Chevy parts as possible. Also would an nv4500 be a transmission option? Just thinking about this and am open to any ideas or advice.

11-03-2018, 04:28 PM	#2
Killer Bee Registered User Join Date: Jan 2016 Location: Barber City, CA Posts: 4,795	Re: Will a 205 hold up? when I was entertaining a Dmax/Allison swap into a 71 K20, I found nothing on the shelf to hook up to an np205.. called several vendors, advanced, dirty laundry or something, diesel experts something, etc.. nothing allison to np205.. a saavy vendor down south recommended to look for later model mopar stuff, np 241 or something like that, also RH drop.. gal on the phone and her husband in the background spent at least 10 minutes giving me a laundry list of specifics.. still need adapters and speed sensor mod, etc.. couple of $k but at least doable.. I decided against it, not enough time for all of that, sounds like a good job for retired folks here's the engine/trans I was looking at 07 LBZ Duramax 6 speed Allison good luck! eta: found my scratch paper.. Dave and K.C. GM LAN steering column shifter tow/haul lockup $2500 stand alone J1939 03-09 OE 4wd Allison tail housing, shaft, seal, bearing Dodge motor mounts 89-93/95/98 lower profile 241 adapter $1300 OSS shaft spline RH drop early 90's Dodge 1500/2500 23 spline __________________ *I started out with nothing - and I still have most of it*

11-03-2018, 08:56 PM	#3
feller Registered User Join Date: Feb 2011 Location: madison, IN. Posts: 484	Re: Will a 205 hold up? Sheesh! Thanks for the info, it sounds like dodge or Ford axles, or a divorced transfer case would be better or cheaper. I guess it wouldn't matter and I would probably be the only one who knew. Another option might be a k4500 rollover and just do the frame swap I'd gain IFS from that

11-05-2018, 06:36 PM	#4
Dieselwrencher 6>8 Plugless........ Join Date: Sep 2007 Location: Prairie City, Ia Posts: 17,139	Re: Will a 205 hold up? You can get a 241d transfer case that was used in 86-93 gas 3/4 and 1 ton dodge trucks. This is a RH drop tcase and if you did do a NV4500 you can put the 29 spline input in it. I've heard of guys putting 208s behind allisons with upgraded guts so they can keep rh drop. If I was building a true K40 or K50 I'd be using non 8 lug stuff to stay true to it's rating but that is just me. __________________ Ryan 1972 Chevy Longhorn K30 Cheyenne Super, 359 Inline 6 cylinder, Auto Trans, Tilt, Diesel Tach/Vach, Buckets, Rare Rear 4-link and air ride option Build Thread 1972 GMC Sierra Grande Longhorn 4x4 1972 Chevy Cheyenne Super K20 Long Step side tilt, tach, tow hooks, AC, 350 4 speed 1972 C10 Suburban Custom Deluxe 1969 Chevy milk truck 1971 Camaro RS 5.3 BTR STG3 Cam Super T10 1940 Ford 354 Hemi 46RH Ford 9" on air ride huge project *Tired of spark plugs? Check this out.*

11-05-2018, 07:38 PM	#5
72 k15 Registered User Join Date: Sep 2018 Location: Fargo Posts: 377	Re: Will a 205 hold up? Dont know how to hook it up but, found a cool truck that you might want to take a look at basically the same thing with 2wd https://www.bismanonline.com/baker_m...dually_duramax

11-05-2018, 08:03 PM	#6
sweetk30 Registered User Join Date: May 2012 Location: horseheads,ny rust belt Posts: 2,794	Re: Will a 205 hold up? these guys offer allision to np205 products and shifter cable brackets . https://precisionfabricationplus.com/ but there prices are CRAZY high . lots of there stuff is 2x the price / labor of offroad design stuff . but some stuff ord dosnt offer . there is a guy on the other site that got there cable bracket kit . he was thinking there ally to 205 kit also but for the same basic money he went off road design MAGNUM BOX doubler . since the magnum box uses round 6 pattern it will bolt to about any trans easy . then the np205 bolts behind it with a new input gear that eliminates a coupler sleeve . gets you 1:1 / 2:1 / 2.72:1 / 5.33:1 / TRUE 3 speed box . http://offroaddesign.com/catalog/Magnum%20Box.htm __________________ 77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great.

11-05-2018, 10:21 PM	#7
71blksuper4x4 SWB 4x4 Collector Join Date: Jun 2001 Location: Osage City, KS Posts: 5,155	Re: Will a 205 hold up? A Dodge 29 spline from a First Gen cummins/getrag truck will bolt up, though I believe needs to be clocked. I chose my LB7/Allison/29 spline np205 first with the GM D60. It would need a higher lift than I intended for my crew build. I wound up finding a Ford HP 78-79 D60 and Ford np205. I bought a kit with clocking ring and 29spline input to change the ford case. The ford D60 will help clear the offset oil pan, and get the truck lower to the ground. __________________ TREVOR 1970 CST swb 4x4 (speedwarning,cruise,tilt,tach,8track, original red shoulder belts,tow hooks) 1972 Jimmy (soon to be Hickey cloned) 1971 Cheyenne Super 4x4 swb (tilt,tach,buckets, original blue shoulder belts,am/fm,cruise,tow hooks, dealer 8 track) 1972 Cheyenne Super K20 4x4 Custom Camper (tilt, tach, am/fm, tow hooks, bed toolbox, aux gas tank 1972 Cheyenne Super Crew Cab K30 4x4 Duramax, Allison, np205, buckets, tow hooks (CURRENT PROJECT) http://67-72chevytrucks.com/vboard/s...d.php?t=624819 1989 V3500 Crew Cab (454tbi, NV4500, np205) 1970 Chevelle SS (LS5 454,th400,8track,buckets,tach) :2004 Jeep Wrangler Rubicon (daily driver) WTB: 1968-70 Cruise Control Lever

11-10-2018, 01:35 AM	#8
1972K20 Registered User Join Date: Nov 2010 Location: Alabama Posts: 740	Re: Will a 205 hold up? Even if you get the NP205 mated up to the Allison, you still have to overcome the issue with the VSS to get it to play nice with the Allison TCM in 4low. Why not use a 2wd Allison and divorce mount the NP205? That way the VSS sensor can stay in the trans and there will be no issue. The 2005-2008 Kodiak's that where 4x4 I think that had a divorced transfer-case setup...not 100% sure though.

01-04-2019, 07:51 PM	#10
6BT 56 Registered User Join Date: Dec 2012 Location: Coldwater On. Canada Posts: 551	Re: Will a 205 hold up? Sounds like a cool build to me . I'd like to do similar. I'd like to build something 4500 or 5500 ish with a c50 cab and big fenders on it . I'm thinking f550 chassis. It's plenty tough . Has much bigger than 1 ton axles , 19.5 wheels etc. And junk blown up 6.0 superdutys are everywhere cheap. I'd like to do a cummins build. Motor mounts etc are easily available for that chassis and cummins drive lines are the proper side drop for that axle and t case . Koop us posted �� __________________ 56 gmc 4X4 Cummins 5 spd 60F 70R 2005 Ram 3500 DRW cummins 4X4. 2006 Conolift 9/15. 2011 F 350 winter beater New 2018 ram 3500 drw 4x4. Makes my 2005 Look as if it's been running on 4 cyl since new ! My Build http://67-72chevytrucks.com/vboard/s...d.php?t=556908

01-06-2019, 04:08 PM	#11
74project Registered User Join Date: May 2009 Location: Las Vegas Posts: 216	Re: Will a 205 hold up? So what is the best trans/transfer case option for a cummins swap for a crew cab? So much info on this topic....

01-07-2019, 11:40 PM	#12
Dieselwrencher 6>8 Plugless........ Join Date: Sep 2007 Location: Prairie City, Ia Posts: 17,139	Re: Will a 205 hold up? I'm not sure there is a best really. Personal preference and parts availability has a lot to do with it. Just my .02. __________________ Ryan 1972 Chevy Longhorn K30 Cheyenne Super, 359 Inline 6 cylinder, Auto Trans, Tilt, Diesel Tach/Vach, Buckets, Rare Rear 4-link and air ride option Build Thread 1972 GMC Sierra Grande Longhorn 4x4 1972 Chevy Cheyenne Super K20 Long Step side tilt, tach, tow hooks, AC, 350 4 speed 1972 C10 Suburban Custom Deluxe 1969 Chevy milk truck 1971 Camaro RS 5.3 BTR STG3 Cam Super T10 1940 Ford 354 Hemi 46RH Ford 9" on air ride huge project *Tired of spark plugs? Check this out.*

01-08-2019, 07:42 AM	#13
71blksuper4x4 SWB 4x4 Collector Join Date: Jun 2001 Location: Osage City, KS Posts: 5,155	Re: Will a 205 hold up? The Allison will hook up fine to the 29 spline np205, there are a couple adapters for the job on the market. You will need more lift on a GM Dana axle then Ford axle. The oil pan is offset to clear a driver side driveshaft. There is a guy who sells an aftermarket oil pan for clearance though. As far as getting past the 4 Lo/Reverse issue, you put the VSS in the tailsection of the Tranny and not in the tcase. Trevor __________________ TREVOR 1970 CST swb 4x4 (speedwarning,cruise,tilt,tach,8track, original red shoulder belts,tow hooks) 1972 Jimmy (soon to be Hickey cloned) 1971 Cheyenne Super 4x4 swb (tilt,tach,buckets, original blue shoulder belts,am/fm,cruise,tow hooks, dealer 8 track) 1972 Cheyenne Super K20 4x4 Custom Camper (tilt, tach, am/fm, tow hooks, bed toolbox, aux gas tank 1972 Cheyenne Super Crew Cab K30 4x4 Duramax, Allison, np205, buckets, tow hooks (CURRENT PROJECT) http://67-72chevytrucks.com/vboard/s...d.php?t=624819 1989 V3500 Crew Cab (454tbi, NV4500, np205) 1970 Chevelle SS (LS5 454,th400,8track,buckets,tach) :2004 Jeep Wrangler Rubicon (daily driver) WTB: 1968-70 Cruise Control Lever

01-09-2019, 12:19 AM	#14
burnin oil Registered User Join Date: Jan 2013 Location: Eastern TN Posts: 1,921	Re: Will a 205 hold up? The Kodiak xfer case was a divorced mounted NP271. It is rare as hens teeth and the input parts are discontinued. I tried to find one about 5 years ago and gave up. As far as transfer cases go the NP271/273 are stronger than a 205. They are beasts. My Dodge 5500 has been putting over 1000 ftlbs though one for the last 10 years. Truck is a G56 (6spd manual) with a dual clutch and factory 4.44s. Wieghs 12k empty and has grossed 36k for thousands of miles. Alot of people talk down on the Dodge 241s also. My 95 2500 still has the original case (non HD so not the wider chain) at 320k and needed rebuilt, still does, when I bought it 100k miles ago. It is still kicking behind a 750 rear wheel HP 12 valve. The NV4500 was making death noises under boost so it got swapped for a G56. Ironically the NV4500 is now in my DD 72 K20 with a built 400SBC with no issues. I guess it was just to worn out for holding 1500 ftlbs of torque.



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