Author Topic: 85 3/4 ton 5 speed swap  (Read 16592 times)

Offline heavychevy

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85 3/4 ton 5 speed swap
« on: January 09, 2010, 01:53:17 am »
im wanting to put a5speed out of a 93 z71 ithink its a nv 4500 with transfercase into my 85 3/4 ton 2wd it has a 355/th400 in it now can  use the pedals outa the z71 in my 85 has anyone done this swap

Offline Irish_Alley

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Re: 85 3/4 ton 5 speed swap
« Reply #1 on: January 09, 2010, 02:35:02 am »
well the transfer case if on the wrong side don't know if you wanna stick to 4x2 or swap it over to 4x4 if you swap it, you have to get a new tail shaft which i think you have to take apart you tranny for that. can't help you with the pedals but i think it might be easer to find a 73-87 to use those pedals and stuff also you have to think about the hydraulics
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Offline heavychevy

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Re: 85 3/4 ton 5 speed swap
« Reply #2 on: January 09, 2010, 10:30:59 am »
yea im stayin 2wd will the pedals of myz71  bolt up ?

Offline Irish_Alley

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Re: 85 3/4 ton 5 speed swap
« Reply #3 on: January 09, 2010, 11:21:26 pm »
to tell you the truth i cant help you on that one
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Offline Captkaos

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Re: 85 3/4 ton 5 speed swap
« Reply #4 on: January 11, 2010, 03:21:16 pm »
Pedals mount differently.  Unless you plan to custom mount them is it easier to user factory 73-87 pieces.

Offline cdpence69

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Re: 85 3/4 ton 5 speed swap
« Reply #5 on: January 11, 2010, 09:03:03 pm »
dang that is going to be a lotta choppin and welding

Offline heavychevy

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Re: 85 3/4 ton 5 speed swap
« Reply #6 on: January 11, 2010, 09:46:44 pm »
finnaly got the clutch pedal off to day it looks like i only need to make a bracket for the top 2 holes there are 2 studs that go through the firewall for master cylinder i was gona drill em out an fab a bracketup  for the other two bolt holes easier said then done huh

Offline grandfisher

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Re: 85 3/4 ton 5 speed swap
« Reply #7 on: January 15, 2010, 08:28:58 pm »
im wanting to put a5speed out of a 93 z71 ithink its a nv 4500 with transfercase into my 85 3/4 ton 2wd it has a 355/th400 in it now can  use the pedals outa the z71 in my 85 has anyone done this swap

I just completed this swap.  Find a salvage yard and get the pedal hanger assembly from a truck equipped with a hydraulic clutch.  I believe anything later than 83 or 85 will be hydraulic.  They will have two reinforcement arms with studs that the master cylinder will mount to.  You will need to drill a 1 1/4 inch hole (if I remember correctly) right between the hole where the speedo cable comes through the firewall and the top left corner of the fuse box.  The fuse box on the 85 may be positioned a little different than my 76 though.  This hole is for the master cylinder. Once you put the master in, you'll be able to tell where the reinforcement rods need to be located.  Actually, I think the 85 will already have the holes marked with dimples.  Don't try to get by without the reinforcement rods.  Eventually, the force of the clutch pedal will fracture the firewall.  If the Z71 that the tranny came out of wasn't a 3/4 or 1 ton, it's probably an NV3500.  The clutch deal is minor though.  If it is indeed and NV4500 and it's a 4x4 version, you'll also want to get a transmission crossmember out of a 85-87 chevy equipped with an NP208 transfer case (aluminum).  The crossmember will wold directly to the NV4500.  You'll also have to cut quite a bit of your floor pan out to allow for the extra height and length of the transmission/transfer.  You'll also have to have your driveshaft shortened.
You'd probably be time and money ahead to find a 2wd transmission.  It would make things a little simpler.  An automatic to manual swap is no big deal though.  Good luck and have fun.
1976 Chevy Crew Cab K2500
  4x4, NV4500, NP208, 454, 7:73 Gears
1987 Chevy Silverado C1500
  5.7L, SM465, 3:08 Gears

Offline heavychevy

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Re: 85 3/4 ton 5 speed swap
« Reply #8 on: January 15, 2010, 11:12:40 pm »
thanks for he info /i wanted to keep thet case on so i could have  the option goin 4x4 later and havin 2 low what trans would have the np 208 on it ?

Offline heavychevy

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Re: 85 3/4 ton 5 speed swap
« Reply #9 on: January 15, 2010, 11:14:20 pm »
my trans has a removable belhousing and iron case maybe a nv4500 ar they pretty stong

Offline grandfisher

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Re: 85 3/4 ton 5 speed swap
« Reply #10 on: January 16, 2010, 10:56:03 am »
The NP208 came behind SM465 4 speed manual transmissions that were equipped with a hydraulic clutch.  Also it came behind mid to late 80s equipped with TH400.  I've heard that the 208s that were mated to TH400s had a different length input shaft.  I'm not sure though.  But I know that the 208 from an SM465 will bolt right up.  The 208 must have a 6 hole, round mounting pattern.  Also it mus have a 32 spine, female input shaft.  A hydraulic clutch equipped manual 4 speed will have the transfer you need.  Also it is an aluminum transfer case.
If your transmission is a 5 speed, cast iron case with a detachable bell housing out of a 93, you got an NV4500 and yes they are strong.  They put them in K3500 HD Chevys and also behind the Cummins engine.  NV4500s are synchronized in every gear but the 1996 and earlier chevy 4500s were not synchronized in reverse.  You should be able to use the bellhousing you have as long as your truck is a 2wd.
You won't be able to use the transfer case that you already have if you plan on converting to 4x4 at a later date.  The transfer case from the 93 is most likely an NP241 and it has a driver's side 4x4 output.  You'll have to obtain an NP208 if you'd like to convert later.  You can also use a late model NP205(bulletproof) but they are extremely hard to find with the correct mounting pattern and input shaft. 
What you might want to do is go ahead and use the transmission and transfer you have(out of the 93) and then if you decide to convert to 4x4, you can worry about locating an NP208.  They're not hard or expensive to find.  If your NV4500 has an external passenger side slave cylinder, it will potentially interfere with your 4x4 shaft if you convert later.  You can get an aftermarket bellhousing for about 318-400 bucks complete with dust shield and throwout arm. 
1976 Chevy Crew Cab K2500
  4x4, NV4500, NP208, 454, 7:73 Gears
1987 Chevy Silverado C1500
  5.7L, SM465, 3:08 Gears

Offline heavychevy

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Re: 85 3/4 ton 5 speed swap
« Reply #11 on: January 30, 2010, 02:47:21 pm »
WHAT ALL HAS  TO COME OUT ,I FINALLY FOUND AN 86 WITH A HYDRO CLUTCH BUT IT LOOKS LIKE I NEED TO PULL THE WHOLE STEERING COLUM BRACKET , IS IT JUST 1 PEICE IT LOOKS LIKE THE CLUTCH HANGER IS WELDED TO IT IM KINDA LOST NOW



Offline Captkaos

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Re: 85 3/4 ton 5 speed swap
« Reply #12 on: January 30, 2010, 07:43:10 pm »
Pull the brake booster off, (6 bolts) pull all the linkage off and drop the clutch/brake pedal assembly.  You may have to drop the steering column down.

Offline heavychevy

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Re: 85 3/4 ton 5 speed swap
« Reply #13 on: February 15, 2010, 10:44:52 pm »
well i thaught it was a hydro  clutch but it isnt its a manual linkage will the hanger assembly still work if i get the master cyl for an hydro clutch and make the support rods

Offline frito-bandito

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Re: 85 3/4 ton 5 speed swap
« Reply #14 on: February 17, 2010, 02:16:25 am »
I don't think so, its not worth the trouble to modify a linkage type setup for hydraulic clutch.
1981 Chevy dually 350 4spd. (One piece at a time)
1994 GMC C1500 4.3L 4L60E. (340K Daily Driver/Resto-Mod)
1998 GMC C1500 5.0L 4L60E (179K Daily Driver)