68 Chevy 20 Project - The 1947 - Present Chevrolet & GMC Truck Message Board Network

hcgviper · 01-19-2006, 11:05 PM

I have reviewed some posts on driveshafts but curious about something, can someone give some advise pertaining to 1 peice versus 2 peice? I am thinking about converting to a single drive shaft on my truck when I rebuild it. Is this going to be a lot of work in regards of machining to make one fit and function correctly? I plan to beef up the frame, and drop a nice muscle motor to back the 4.58 gears.

One other question in 68 did they have limited slip or am I correct to assume this is a posi track [3/4 ton rear]

Any advise will be appriciated, this is my first project from the ground up.

Brad · 01-20-2006, 03:39 AM

Welcome to the board from the Pacific NW! Try doing a search on the board. This was recently covered in a post. You'll find a 50/50 split on whether to keep the 2 piece or go with a 1 piece driveshaft. Properly rebuilt, a 2 piece will last another 30 years. However, it can be expensive and I prefer a 1 piece myself. I had one in a C-10 LWB for years w/6cyl and it was soooo much better considering I never had to replace any carrier bearings or fear they'd leave me stranded again. I had 3 go out on me within the same amount of years. The 1 piece will be easy to measure for and no problem to make, but you'll have to completely remove all the bracketry for the carrier bearing mounts. Given your goals, I might stick with the 2 piece and have it rebuilt by a good shop.

**special-K** · 01-20-2006, 08:07 AM

Welcome to "The Right Place for old GM Haulers".
I think all the 1pc vs 2pc talk is on shortbeds.Mostly when converting a 6cyl/3spd(1pc) to V8/auto and keeping the 1pc.The longbeds are best with the 2pc that they came with,especially if you want to lower the truck.
You need to identify your rear.I would assume you have an Eaton HO52(round diff cover)which might have 4.57 gearing.Is there a "No-Spin" listed as an option?Or,is there a sticker on the inside/back of the cab on the passenger side.These are posi-trac.

hcgviper · 01-20-2006, 11:03 PM

I found some type of sticker behind the passenger side of seat it talks about how to setup the jack for tire replacement. Also looking at the rear the cover looks like a giant half of a basket ball. Looks like 10 bolts holding the cover 3 on top 3 on bottom and 2 on each side.

jacobs · 01-20-2006, 11:43 PM

Pickups with rear leaf springs were factory equipped with a one piece driveshaft, pickups with rear coil springs were factory equipped with two piece driveshafts. The reason for the two piece driveshafts w/coils was due to the additional crossmember needed in that application.

Longhorn Man · 01-20-2006, 11:53 PM

jacobs, that is not very acurate.
There was more to it than what kind of springs on the truck.
There were NO C/20 trucks, nor C/10 LWB trucks that had a singe driveshaft, they ALL had 2 piece, regardless of the springs.
Also, on the SWB trucks, there were plenty made in either configuration, again, with no regards to the springs. My old 69 SWB GMC was originally a 305 V6 / TH400 truck, and had a single shaft.

jacobs · 01-21-2006, 12:25 AM

Quote:

Originally Posted by Longhorn Man

jacobs, that is not very acurate.
There was more to it than what kind of springs on the truck.
There were NO C/20 trucks, nor C/10 LWB trucks that had a singe driveshaft, they ALL had 2 piece, regardless of the springs.

Back in the 1970's I wrenched for a construction company that had a fleet of LWB C10, and C20 pickups with the optional factory leaf springs. They ALL had one piece driveshafts.

Longhorn Man · 01-21-2006, 01:11 AM

were they 67 - 72?
With the automatics, the 67 - 72 trucks all had short shaft trannys... both the TH350 and TH400. Woth that, and the location of the engines being further forward than later trucks (73 to date) that placed the tranny more than 6 feet from the rear axle, and that 6 foot length is the number where OEM's stopped back in the day, they didn't start making them longer untill recent years after going to alluminum drive shafts. Most custom drive shaft places wont do it even today.
Do a poll on here and see how many of the 20,000 members here have an original one piece shaft on a 67 - 72, 2 wheel drive lwb anything... I'll bet a kick to the daddy parts, no one will have one.

jacobs · 01-21-2006, 08:11 AM

They were 1969, 1970, and 1971 Chevrolet C10's and C20's with 350 ci engines, TH350's and 465 4 speeds. As I said in the previous post they were ALL 8' beds (LWB), factory installed leaf springs, AND ONE PIECE DRIVESHAFTS. They hadn't been hacked on by a dozen previous owners. They were original!

Check an original old Chevy parts book not an aftermarket supplier - YOU WILL FIND THEM!

Tx Firefighter · 01-28-2006, 08:06 PM

Quote:

Originally Posted by jacobs

They were 1969, 1970, and 1971 Chevrolet C10's and C20's with 350 ci engines, TH350's and 465 4 speeds. As I said in the previous post they were ALL 8' beds (LWB), factory installed leaf springs, AND ONE PIECE DRIVESHAFTS. They hadn't been hacked on by a dozen previous owners. They were original!

Check an original old Chevy parts book not an aftermarket supplier - YOU WILL FIND THEM!

I've never seen an SM465 in one of these trucks with a slip yoke, which you'd need for a 1 piece shaft.

**special-K** · 01-21-2006, 10:14 AM

No pissin` matches,right?The rules?All of my 2wd longbeds have had 2-pc,I buy parts from the GM parts counter.I`m not saying one way or another,but...I`ve forgotten as much as I`ve learned since I`ve grown older along side of these trucks.I`ve relearned or learned what I never pieced together(or didn`t care)about these trucks here on these posts.Can we post a poll on who has what?
Hcgviper,you have the HO52.Do you have coil springs or leafs?The 2pc driveshaft can handle all the power you can throw at it.I would suggest leaving it as is and giving it all new upgrade parts.Jack up one side of the rear and see if you can spin the wheel.Try to really spin it.If it won`t spin at all you have a posi.The sticker that would be by your jacking instructions would be warning you to not run the truck in gear while a rear wheel is jacked.With posi,it would drive off the jack.Another way to check for posi/limited-slip is,get on grass or loose dirt/gravel and stomp on it.If both tires spin,you got traction-assist.Hit the throttle a little easier so it barely breaks loose.If the second wheel starts grabbing right after the first one breaks,you have limited-slip.If both break loose together,it`s posi.If there never was a sticker,you probably don`t have either,unless someone added it.It`s hard to find a posi for those rears.Although,14-bolt carriers have been known to find their way into HO52s.
One more question.Where`s Hutto?

jacobs · 01-21-2006, 11:34 AM

..

hcgviper · 01-22-2006, 12:44 PM

I see the coil springs with some type of additional support coming off the frame to the rear axle. As for the spinning of the tires I will find out more when I start the tear down process. I am looking foward to getting this project going. I will stick with your advise and rebuild the 2piece, do you feel confident it will handle the horsepower of a BB or whatever I want to throw at it?

Hutto is in Texas North of Austin.

Longhorn Man · 01-22-2006, 03:39 PM

A properly built 2 piece will handle way more than your chassis can. Every straight truck and semi that you'll see on the road has them, and, while they are bigger, they last 100K at a minimum.

wlarue72 · 01-22-2006, 05:00 PM

72 LWB ...leaf springs....two-piece shaft.

**special-K** · 01-22-2006, 07:59 PM

Yes,a 2pc can handle as much as a one pc.

Buckman · 01-22-2006, 08:48 PM

71 GMC....SWB....2 piece shaft...leaf springs

Longhorn Man · 01-22-2006, 10:38 PM

3 longhorns all with 2 piece shafts, all with leafs. (duh) 1 SWB 69 GMC , coils, single shaft.

hcgviper · 01-28-2006, 07:12 PM

I thank you all for the information on this and will be tapping you in the furture for my first project truck. Any information is greatly appriciated, one note though; I am not a Longhorn....

67-72williso · 01-28-2006, 07:46 PM

The only truck I had with a 1 pc drive shaft was a 72 swb 6 banger 3 on the tree, rear (coil).
Later Willis

Longhorn Man · 01-28-2006, 08:42 PM

<----what is that?

GMCMAX · 01-28-2006, 09:28 PM

Ihave: 68 GMC LWB 4 speed leaf w/2piece.... 69 Chevy LWB TH400 Coil 2 piece

Longhorn Man · 01-28-2006, 09:30 PM

like I said, you won't find a LWB 67 - 72 2 wheel drive with an original one piece shaft... period.

Tx Firefighter · 01-28-2006, 09:31 PM

I reread this whole post, and I stand behind Andy on his statements. He and I have been rubbing online elbows for 2.5 years now, and we see eye to eye about 95 percent of the time, even if he does live up in that god forsaken place.

stllookn · 01-28-2006, 09:56 PM

'69 LWB coil 2-piece, '67 LWB coil 2-piece, '67 SWB coil 1-piece, (2) '68 Longhorns 2-piece, (1) '72 Longhorn 2-piece...all original.

Maybe those were COPO fleet trucks?

01-19-2006, 11:05 PM	#1
hcgviper Registered User Join Date: Jan 2006 Location: Hutto Posts: 4	68 Chevy 20 Project I have reviewed some posts on driveshafts but curious about something, can someone give some advise pertaining to 1 peice versus 2 peice? I am thinking about converting to a single drive shaft on my truck when I rebuild it. Is this going to be a lot of work in regards of machining to make one fit and function correctly? I plan to beef up the frame, and drop a nice muscle motor to back the 4.58 gears. One other question in 68 did they have limited slip or am I correct to assume this is a posi track [3/4 ton rear] Any advise will be appriciated, this is my first project from the ground up. Last edited by hcgviper; 01-19-2006 at 11:05 PM.

01-20-2006, 03:39 AM	#2
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,673	Re: 68 Chevy 20 Project Welcome to the board from the Pacific NW! Try doing a search on the board. This was recently covered in a post. You'll find a 50/50 split on whether to keep the 2 piece or go with a 1 piece driveshaft. Properly rebuilt, a 2 piece will last another 30 years. However, it can be expensive and I prefer a 1 piece myself. I had one in a C-10 LWB for years w/6cyl and it was soooo much better considering I never had to replace any carrier bearings or fear they'd leave me stranded again. I had 3 go out on me within the same amount of years. The 1 piece will be easy to measure for and no problem to make, but you'll have to completely remove all the bracketry for the carrier bearing mounts. Given your goals, I might stick with the 2 piece and have it rebuilt by a good shop. __________________ 1968 C-10 SWB, 5.7 Vortec/700R4/3.73 posi, Torch Red 1968 Camaro, 250/Powerglide, all original (No, I'm not gonna drop a 350 in it!...Jeez!) 2000 Honda VFR in the faster yellow! 2008 Husqvarna TE-610 1967 C-10 SWB 'Six Appeal'-Gone but not forgotten...

01-20-2006, 08:07 AM	#3
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,852	Re: 68 Chevy 20 Project Welcome to "The Right Place for old GM Haulers". I think all the 1pc vs 2pc talk is on shortbeds.Mostly when converting a 6cyl/3spd(1pc) to V8/auto and keeping the 1pc.The longbeds are best with the 2pc that they came with,especially if you want to lower the truck. You need to identify your rear.I would assume you have an Eaton HO52(round diff cover)which might have 4.57 gearing.Is there a "No-Spin" listed as an option?Or,is there a sticker on the inside/back of the cab on the passenger side.These are posi-trac. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ Last edited by special-K; 01-21-2006 at 10:19 AM.

01-20-2006, 11:03 PM	#4
hcgviper Registered User Join Date: Jan 2006 Location: Hutto Posts: 4	Re: 68 Chevy 20 Project I found some type of sticker behind the passenger side of seat it talks about how to setup the jack for tire replacement. Also looking at the rear the cover looks like a giant half of a basket ball. Looks like 10 bolts holding the cover 3 on top 3 on bottom and 2 on each side.

01-20-2006, 11:43 PM	#5
jacobs Registered User Join Date: Sep 2005 Location: 9000' Mountain Man Posts: 326	Re: 68 Chevy 20 Project Pickups with rear leaf springs were factory equipped with a one piece driveshaft, pickups with rear coil springs were factory equipped with two piece driveshafts. The reason for the two piece driveshafts w/coils was due to the additional crossmember needed in that application.

01-20-2006, 11:53 PM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 68 Chevy 20 Project jacobs, that is not very acurate. There was more to it than what kind of springs on the truck. There were NO C/20 trucks, nor C/10 LWB trucks that had a singe driveshaft, they ALL had 2 piece, regardless of the springs. Also, on the SWB trucks, there were plenty made in either configuration, again, with no regards to the springs. My old 69 SWB GMC was originally a 305 V6 / TH400 truck, and had a single shaft.

01-21-2006, 01:11 AM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 68 Chevy 20 Project were they 67 - 72? With the automatics, the 67 - 72 trucks all had short shaft trannys... both the TH350 and TH400. Woth that, and the location of the engines being further forward than later trucks (73 to date) that placed the tranny more than 6 feet from the rear axle, and that 6 foot length is the number where OEM's stopped back in the day, they didn't start making them longer untill recent years after going to alluminum drive shafts. Most custom drive shaft places wont do it even today. Do a poll on here and see how many of the 20,000 members here have an original one piece shaft on a 67 - 72, 2 wheel drive lwb anything... I'll bet a kick to the daddy parts, no one will have one.

01-21-2006, 08:11 AM	#9
jacobs Registered User Join Date: Sep 2005 Location: 9000' Mountain Man Posts: 326	Re: 68 Chevy 20 Project They were 1969, 1970, and 1971 Chevrolet C10's and C20's with 350 ci engines, TH350's and 465 4 speeds. As I said in the previous post they were ALL 8' beds (LWB), factory installed leaf springs, AND ONE PIECE DRIVESHAFTS. They hadn't been hacked on by a dozen previous owners. They were original! Check an original old Chevy parts book not an aftermarket supplier - YOU WILL FIND THEM! Last edited by jacobs; 01-21-2006 at 08:15 AM.

01-21-2006, 10:14 AM	#11
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,852	Re: 68 Chevy 20 Project No pissin` matches,right?The rules?All of my 2wd longbeds have had 2-pc,I buy parts from the GM parts counter.I`m not saying one way or another,but...I`ve forgotten as much as I`ve learned since I`ve grown older along side of these trucks.I`ve relearned or learned what I never pieced together(or didn`t care)about these trucks here on these posts.Can we post a poll on who has what? Hcgviper,you have the HO52.Do you have coil springs or leafs?The 2pc driveshaft can handle all the power you can throw at it.I would suggest leaving it as is and giving it all new upgrade parts.Jack up one side of the rear and see if you can spin the wheel.Try to really spin it.If it won`t spin at all you have a posi.The sticker that would be by your jacking instructions would be warning you to not run the truck in gear while a rear wheel is jacked.With posi,it would drive off the jack.Another way to check for posi/limited-slip is,get on grass or loose dirt/gravel and stomp on it.If both tires spin,you got traction-assist.Hit the throttle a little easier so it barely breaks loose.If the second wheel starts grabbing right after the first one breaks,you have limited-slip.If both break loose together,it`s posi.If there never was a sticker,you probably don`t have either,unless someone added it.It`s hard to find a posi for those rears.Although,14-bolt carriers have been known to find their way into HO52s. One more question.Where`s Hutto? __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ Last edited by special-K; 01-21-2006 at 10:18 AM.

01-21-2006, 11:34 AM	#12
jacobs Registered User Join Date: Sep 2005 Location: 9000' Mountain Man Posts: 326	Re: 68 Chevy 20 Project .. Last edited by jacobs; 09-23-2006 at 01:06 PM.

01-22-2006, 12:44 PM	#13
hcgviper Registered User Join Date: Jan 2006 Location: Hutto Posts: 4	Re: 68 Chevy 20 Project I see the coil springs with some type of additional support coming off the frame to the rear axle. As for the spinning of the tires I will find out more when I start the tear down process. I am looking foward to getting this project going. I will stick with your advise and rebuild the 2piece, do you feel confident it will handle the horsepower of a BB or whatever I want to throw at it? Hutto is in Texas North of Austin. Last edited by hcgviper; 01-22-2006 at 01:46 PM.

01-22-2006, 03:39 PM	#14
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 68 Chevy 20 Project A properly built 2 piece will handle way more than your chassis can. Every straight truck and semi that you'll see on the road has them, and, while they are bigger, they last 100K at a minimum.

01-22-2006, 05:00 PM	#15
wlarue72 Registered User Join Date: Nov 2002 Location: DFW Texas Posts: 244	Re: 68 Chevy 20 Project 72 LWB ...leaf springs....two-piece shaft. __________________ 72 Cheyenne Super 402 daily driver. A lifetime project!

01-22-2006, 07:59 PM	#16
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,852	Re: 68 Chevy 20 Project Yes,a 2pc can handle as much as a one pc. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

01-22-2006, 08:48 PM	#17
Buckman Registered User Join Date: Sep 2005 Location: bedford Indiana Posts: 70	Re: 68 Chevy 20 Project 71 GMC....SWB....2 piece shaft...leaf springs



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01-22-2006, 10:38 PM	#18
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 68 Chevy 20 Project 3 longhorns all with 2 piece shafts, all with leafs. (duh) 1 SWB 69 GMC , coils, single shaft.

01-28-2006, 07:12 PM	#19
hcgviper Registered User Join Date: Jan 2006 Location: Hutto Posts: 4	Re: 68 Chevy 20 Project I thank you all for the information on this and will be tapping you in the furture for my first project truck. Any information is greatly appriciated, one note though; I am not a Longhorn.... Last edited by hcgviper; 01-28-2006 at 07:15 PM.

01-28-2006, 07:46 PM	#20
67-72williso Junk/Daily Driver Club Join Date: Feb 2004 Location: Manheim, PA 17545 Posts: 253	Re: 68 Chevy 20 Project The only truck I had with a 1 pc drive shaft was a 72 swb 6 banger 3 on the tree, rear (coil). Later Willis __________________ Daily Driver: 1970 C-20 400 sbc,sm-465,Dana 61 one ton SRW rear, 3.07 gears, locker. There are three kinds of people: those who make things happen, those who watch things happen, and those who have no idea what happened!

01-28-2006, 08:42 PM	#21
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 68 Chevy 20 Project <----what is that?

01-28-2006, 09:28 PM	#22
GMCMAX Active Member Join Date: Jan 2006 Location: Lower Mid-East Ca. Posts: 326	Re: 68 Chevy 20 Project Ihave: 68 GMC LWB 4 speed leaf w/2piece.... 69 Chevy LWB TH400 Coil 2 piece __________________ Never try to teach a pig to sing; it wastes your time and annoys the pig! Gets More Chicks My lugnuts require more torque than your honda makes! 68 GMC, 4X4 conversion w/73 k20 running gear and springs, 350 4spd, 4.10's, D44 powerlok front, 14BFF govlock rear, 33" tires, lifted 4".

01-28-2006, 09:30 PM	#23
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 68 Chevy 20 Project like I said, you won't find a LWB 67 - 72 2 wheel drive with an original one piece shaft... period.

01-28-2006, 09:31 PM	#24
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: 68 Chevy 20 Project I reread this whole post, and I stand behind Andy on his statements. He and I have been rubbing online elbows for 2.5 years now, and we see eye to eye about 95 percent of the time, even if he does live up in that god forsaken place. __________________ I'm on the Instagram- @Gearhead_Kevin

01-28-2006, 09:56 PM	#25
stllookn Saving 1 truck at a time! Join Date: Aug 2001 Location: Kent, WA Posts: 6,465	Re: 68 Chevy 20 Project '69 LWB coil 2-piece, '67 LWB coil 2-piece, '67 SWB coil 1-piece, (2) '68 Longhorns 2-piece, (1) '72 Longhorn 2-piece...all original. Maybe those were COPO fleet trucks? __________________ '68 C20 Longhorn 50th Anniversary 400/TH400 '68 C20 Longhorn 50th Anniversary 468/TH400w/buckets '72 C20 Halfhorn (Longhorn w/o cab and front clip) '69 Flxible Cruiser (look up ugly in the dictionary) Last edited by stllookn; 01-28-2006 at 10:28 PM.

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