Rear Axel Conversion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bluec10 · 03-31-2006, 10:42 PM

I want to swap a 5 bolt rear end into my '69 GMC. Right now I have a L6 engine in the truck which will remain for a while. Eventually I'd like a hot 350 or 383. Any suggestions? What will fit?

HeavyD · 04-01-2006, 02:31 AM

How soon do you want to do this? Once the snow goes I will be parting a 71Chev if you want to buy a whole rear drum to drum. I know we don't live that close, but maybe we could work something out. I also have a complete disc front suspension of you don't already have a set up as well.

72armyswbtruck · 04-01-2006, 04:22 AM

Why not just switch out just the spidel axels. It's not really all that difficult of a switch, however the easiest is swapping the entire axel from wheel to wheel

Brad · 04-01-2006, 12:30 PM

Early 1970's axle's will be a direct swap for you. This changes them from 6 lug to 5 lug. About mid year in 1970 they went with the longer housing of 71 and up. They'll still fit, but will stick out farther about 3/4" on each side and I've been told the bearings will ride on a non-hardened part of the axle. Many folks have done it, but do a search and you'll find some input on this if you plan on doing it.

Tx Firefighter · 04-01-2006, 01:22 PM

Brad, you're mistaken. 70's were all still 5 lug, both early short axles, and longer late axles, all 6 lug.

It's getting harder to find 71-72 rearends around here. Seems lots of folks have used them all up converting stuff to five lug over the years. I'm putting a 75 model rear under my truck right now. I'm having to deal with the funny coil spring axle saddles and the panhard bar mount. Once I get it done, I'll post an FAQ article with pictures outlining it all. It's doable, but much easier and cheaper to just find a 71-72 rearend if you can.

bluec10 · 04-02-2006, 11:45 PM

Quote:

Originally Posted by Tx Firefighter

Brad, you're mistaken. 70's were all still 5 lug, both early short axles, and longer late axles, all 6 lug.

It's getting harder to find 71-72 rearends around here. Seems lots of folks have used them all up converting stuff to five lug over the years. I'm putting a 75 model rear under my truck right now. I'm having to deal with the funny coil spring axle saddles and the panhard bar mount. Once I get it done, I'll post an FAQ article with pictures outlining it all. It's doable, but much easier and cheaper to just find a 71-72 rearend if you can.

This is exactly my problem. The 71-72 rear ends are tough to find. I've gone with front end parts from an '84 and found that the fit is almost perfect - I only had to drill 2 holes. I'm looking forward to viewing your FAQ article - thanks for making the effort. One last thing...what about axel ratios?

Brad · 04-03-2006, 02:50 AM

Quote:

Originally Posted by Tx Firefighter

Brad, you're mistaken. 70's were all still 5 lug, both early short axles, and longer late axles, all 6 lug.

It's getting harder to find 71-72 rearends around here. Seems lots of folks have used them all up converting stuff to five lug over the years.

I'm confused. Perhaps we're talking apples and oranges, but I keep reading this over and over and it appears bluec10 has 6 lug axles and wants 5 lug axles. I did this swap with my 67 housing using early 70's 5 lug axles since this is a direct bolt in swap. Are we talking the same thing or am I confused regarding the request?

sneakysnake · 04-03-2006, 11:37 AM

Quote:

Originally Posted by Brad

I did this swap with my 67 housing using early 70's 5 lug axles since this is a direct bolt in swap. ?

5 lugs didnt come out until 71'
but in 70' they did have a long and short axle tubes but both were 6 lug, the later 70 is a perfect for inner swap because it was wider and doesnt cause a problem with the brake drums.

Bob Moore · 04-03-2006, 11:40 AM

TexFF - IIR an added bonus to using the newer axle is that larger brakes were available. Am I correct on this?

Brad - I really thought 1/2T trucks were 6 lug through 1970. With disc brakes being introduced in 1971 they went to 5 lug. 4X4 stayed 6 lug in 1/2T.

Brad · 04-03-2006, 03:22 PM

Well, maybe I've forgotten what I did regarding my axles. I know I swapped in 5-lug axles in some sort of housing with the correct length axles, lol

Now I'm curious what housing I used and what I did. It's been about 5 years.

Tx Firefighter · 04-04-2006, 06:16 AM

Bob, I do belive the later axles did all get the bigger brakes. I'll measure it when I get home next time.

03-31-2006, 10:42 PM	#1
bluec10 Registered User Join Date: Apr 2002 Location: Manitoba, Canada Posts: 663	Rear Axel Conversion I want to swap a 5 bolt rear end into my '69 GMC. Right now I have a L6 engine in the truck which will remain for a while. Eventually I'd like a hot 350 or 383. Any suggestions? What will fit? __________________ Present: 2015 Tacoma. Yeah, not a GM, but I love it. 1969 GMC 32,000 - fix, drive, relax, fix... 2019 BMW R1250 GSA - Yahoooooooo 1979 Honda GL 1000 - retro touring at its best. Past: '05 Sierra 4x4 - Had 270,000 KM and running well when it was written-off by a stop sign runner. '94 F-150 from the "F word" company. I'll admit it...good truck. Sold what was left of it for $800 to a guy who came to pick it up at 11:00 PM with cash in hand. Hmm. '79 Sierra Grande (Black) organ donor - perfect rebuildable 4-bolt 350 and a good TH350. '76 Sierra Grande (Orange) - hate isn't too strong a word. Kid who bought it turned it into a hot rod. '68 C-10 R.I.P. - Dad's old truck...too far gone to resurrect. '59 C-50 - with hoist. Truck is gone, wife isn't. Nuff said.

04-01-2006, 02:31 AM	#2
HeavyD Senior Member Join Date: Sep 2004 Location: Wakaw, Sask, Canada Posts: 3,180	Re: Rear Axel Conversion How soon do you want to do this? Once the snow goes I will be parting a 71Chev if you want to buy a whole rear drum to drum. I know we don't live that close, but maybe we could work something out. I also have a complete disc front suspension of you don't already have a set up as well. __________________ "You can take the man out of PA, but you can't take PA out of the man" Last edited by HeavyD; 04-01-2006 at 02:33 AM.

04-01-2006, 04:22 AM	#3
72armyswbtruck Registered User Join Date: Feb 2004 Location: Idaho Posts: 4,034	Re: Rear Axel Conversion Why not just switch out just the spidel axels. It's not really all that difficult of a switch, however the easiest is swapping the entire axel from wheel to wheel __________________ "Remember, They can Kill You, but they can't eat You, That's against the law!!!!!!!!!"

04-01-2006, 12:30 PM	#4
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,673	Re: Rear Axel Conversion Early 1970's axle's will be a direct swap for you. This changes them from 6 lug to 5 lug. About mid year in 1970 they went with the longer housing of 71 and up. They'll still fit, but will stick out farther about 3/4" on each side and I've been told the bearings will ride on a non-hardened part of the axle. Many folks have done it, but do a search and you'll find some input on this if you plan on doing it. __________________ 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...

04-01-2006, 01:22 PM	#5
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: Rear Axel Conversion Brad, you're mistaken. 70's were all still 5 lug, both early short axles, and longer late axles, all 6 lug. It's getting harder to find 71-72 rearends around here. Seems lots of folks have used them all up converting stuff to five lug over the years. I'm putting a 75 model rear under my truck right now. I'm having to deal with the funny coil spring axle saddles and the panhard bar mount. Once I get it done, I'll post an FAQ article with pictures outlining it all. It's doable, but much easier and cheaper to just find a 71-72 rearend if you can. __________________ I'm on the Instagram- @Gearhead_Kevin Last edited by Tx Firefighter; 04-01-2006 at 01:25 PM.

04-03-2006, 11:40 AM	#9
Bob Moore Registered User Join Date: Feb 2004 Location: Tacoma WA Posts: 1,365	Re: Rear Axel Conversion TexFF - IIR an added bonus to using the newer axle is that larger brakes were available. Am I correct on this? Brad - I really thought 1/2T trucks were 6 lug through 1970. With disc brakes being introduced in 1971 they went to 5 lug. 4X4 stayed 6 lug in 1/2T. __________________ 67 C-20 LWB, tilt, speed alert, vac, 454, T400 67 C-10 SWB, factory air with more to follow

04-03-2006, 03:22 PM	#10
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,673	Re: Rear Axel Conversion Well, maybe I've forgotten what I did regarding my axles. I know I swapped in 5-lug axles in some sort of housing with the correct length axles, lol Now I'm curious what housing I used and what I did. It's been about 5 years. __________________ 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...

04-04-2006, 06:16 AM	#11
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: Rear Axel Conversion Bob, I do belive the later axles did all get the bigger brakes. I'll measure it when I get home next time. __________________ I'm on the Instagram- @Gearhead_Kevin



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