th350 to nv4500 swap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

doug70 · 01-10-2010, 10:42 AM

ok, I think I have a plan for the trans.

1993 NV4500, 1993 bellhousing with passenger side slave, clutch and brake pedals from 93, flywheel from 93, new clutch,pp,flywheel,pilot bearing
1971 NP205 8 bolt style(racetrack)
1983 TH400 to NP205 adapter with integrated mount and new special gasket
rebuild np205 and machine for large bearing, install 32 spline input shaft

Put it all together and hope for the best. I have read there may be some driveline clearance issues with the passenger side slave, but not everyone has experienced this problem. I will have to deal with that if it is a problem.

I expect it will take driveshaft modification.

Btw this all goes in a 71 k20.

Did I miss anything?

Doug

duallyjams · 01-10-2010, 11:32 AM

Finding a nv4500 is the hard part everything is down hill from there.

msgross · 01-10-2010, 11:43 AM

advance adapters make a conversion kit.. a few members have the nv4500/205 setup

doug70 · 01-10-2010, 12:28 PM

Thanks, I found a 93 donor truck, that's why I mentioned all 93. I would prefer 96 up, but like you said they are hard to find. My biggest doubt is the th400 adapter on a nv4500. I have seen the 86 up np205 with the th400 mount right up, that's why I think it will work.

Doug

yellow70GMC · 01-10-2010, 04:00 PM

IIRC the NV4500 bolts up directly to a np205 with the long 32 spline input, and the 6 bolt pattern, thats why the 86 up 205's that came with th400s bolt right up.

**hatzie** · 01-12-2010, 10:57 PM

Quote:

Originally Posted by yellow70GMC

IIRC the NV4500 bolts up directly to a np205 with the long 32 spline input, and the 6 bolt pattern, thats why the 86 up 205's that came with th400s bolt right up.

I thought the NV4500 output shaft needed to be shortened to fit up a NP205.
Not modding my $1100 NV4500 was the main reason I went with the 208. The brand new 208 for $180 was the other reason.

yellow70GMC · 01-13-2010, 06:58 PM

Quote:

Originally Posted by hatzie

I thought the NV4500 output shaft needed to be shortened to fit up a NP205.
Not modding my $1100 NV4500 was the main reason I went with the 208. The brand new 208 for $180 was the other reason.

Maybe so. I was talking about the input shaft on the NP205. Early NP205s with a TH400 had a short 32 spline input shaft, 1986 and later model NP205s had a long 32 spline input.

01-10-2010, 10:42 AM	#1
doug70 Registered User Join Date: Nov 2005 Location: Breckenridge, texas Posts: 83	th350 to nv4500 swap ok, I think I have a plan for the trans. 1993 NV4500, 1993 bellhousing with passenger side slave, clutch and brake pedals from 93, flywheel from 93, new clutch,pp,flywheel,pilot bearing 1971 NP205 8 bolt style(racetrack) 1983 TH400 to NP205 adapter with integrated mount and new special gasket rebuild np205 and machine for large bearing, install 32 spline input shaft Put it all together and hope for the best. I have read there may be some driveline clearance issues with the passenger side slave, but not everyone has experienced this problem. I will have to deal with that if it is a problem. I expect it will take driveshaft modification. Btw this all goes in a 71 k20. Did I miss anything? Doug

01-10-2010, 11:32 AM	#2
duallyjams Registered User Join Date: May 2007 Location: Deale Md Posts: 4,663	Re: th350 to nv4500 swap Finding a nv4500 is the hard part everything is down hill from there. __________________ James 63 GMC V6 4speed carryall 65 chevy swb bbw V8 auto 68 K20 327/4 speed, buddy buckets 2002 GMC CC Dually Duramax 64 GMC lwb 3/4 V6 4speed SOLD 66 GMC swb bbw buddy buckets SOLD IG duallyjams The only thing that stays the same is constant change!

01-10-2010, 11:43 AM	#3
msgross Registered User Join Date: Jul 2006 Location: Central PA Posts: 12,201	Re: th350 to nv4500 swap advance adapters make a conversion kit.. a few members have the nv4500/205 setup __________________ The Garage: 1968 K-10 SWB - "Project Money Pit" 1996 Z-71 - "huntin rig" 1969 C-10 LWB (SOLD) "Project flip that truck or else" 1993 Passport, F@rd 1-ton (SOLD)"Project Cousin Eddie" My Garage Build "The 1,000 footer"

01-10-2010, 12:28 PM	#4
doug70 Registered User Join Date: Nov 2005 Location: Breckenridge, texas Posts: 83	Re: th350 to nv4500 swap Thanks, I found a 93 donor truck, that's why I mentioned all 93. I would prefer 96 up, but like you said they are hard to find. My biggest doubt is the th400 adapter on a nv4500. I have seen the 86 up np205 with the th400 mount right up, that's why I think it will work. Doug

01-10-2010, 04:00 PM	#5
yellow70GMC Registered User Join Date: Sep 2005 Location: Reno, NV Posts: 161	Re: th350 to nv4500 swap IIRC the NV4500 bolts up directly to a np205 with the long 32 spline input, and the 6 bolt pattern, thats why the 86 up 205's that came with th400s bolt right up.



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