6 lug square body?
#1
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Car: 1990 c1500
Engine: 357 chevy tbi
Transmission: Built 700r4
Axle/Gears: 3.42
6 lug square body?
So ik this is for third gen stuff but i drive a tbi truck and you guys know alot about the too. Anyway my neighbor had a square body 80s era chevy truck its only good as a parts trck and he may let me buy the rearend and motor out of it for a future project but i would want to put the rearend in my 90 truck. My question is how do i determin the readend ratio? Where is the pro code in my truck its in the glove box but this one seemed to not be there i looked and it had a blue sticker with no codes on it and its a 4x4 and the trearend was 6 lug so whats up with that? I don't know much about a 6 lug rearend. Any ideas?
#3
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Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: 6 lug square body?
6 bolt axles is normally referred to as a heavy half. Still a half ton suspension. Probably just a 8.5" 10 bolt diff. Might be a Dana.
Try doing some research on truck forums that cater to 80's GM pickups since this has nothing to do with third gens.
Try doing some research on truck forums that cater to 80's GM pickups since this has nothing to do with third gens.
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Car: 88 5.7 Iroc
Engine: L98
Transmission: 700R4
Re: 6 lug square body?
1/2 ton 4 X 4 Square bodys came with 6 lug axles all the way from 74 to 87. 80's model trucks came with what was referred to as a corporate 10 bolt. Not quite as strong as a 12 bolt, but stronger than a passenger car 10 bolt. 2WD trucks had 5 lug axles.
Axle ratios can determined buy rotating axle one revolution and count pinion yoke revolutions. Not exact, but will get you in the ballpark.
Axle ratios can determined buy rotating axle one revolution and count pinion yoke revolutions. Not exact, but will get you in the ballpark.
#5
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Car: 1990 c1500
Engine: 357 chevy tbi
Transmission: Built 700r4
Axle/Gears: 3.42
Re: 6 lug square body?
1/2 ton 4 X 4 Square bodys came with 6 lug axles all the way from 74 to 87. 80's model trucks came with what was referred to as a corporate 10 bolt. Not quite as strong as a 12 bolt, but stronger than a passenger car 10 bolt. 2WD trucks had 5 lug axles.
Axle ratios can determined buy rotating axle one revolution and count pinion yoke revolutions. Not exact, but will get you in the ballpark.
Axle ratios can determined buy rotating axle one revolution and count pinion yoke revolutions. Not exact, but will get you in the ballpark.
#6
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Car: 91 Firebird
Engine: 6.0
Transmission: T56
Axle/Gears: 3.73
Re: 6 lug square body?
you could prolly just swap your 5 lug axles into that housing to make it work
the RPO codes are all the same in regards to gear ratios, no matter if it was in a truck, wagon or corvette.
So look at the rpo codes and start googling them. Here is a quick list I found on fullsizechevy.com
GT4 -- AXLE REAR, 3.73 RATIO
GT5 -- AXLE REAR, 4.10 RATIO
GU4 -- AXLE REAR, 3.08 RATIO
GU5 -- AXLE REAR, 3.23 RATIO
GU6 -- AXLE REAR, 3.42 RATIO
G80 -- AXLE REAR, LIMITED SLIP (POSITRACTION)
HC4 -- AXLE REAR, 4.56 RATIO
the RPO codes are all the same in regards to gear ratios, no matter if it was in a truck, wagon or corvette.
So look at the rpo codes and start googling them. Here is a quick list I found on fullsizechevy.com
GT4 -- AXLE REAR, 3.73 RATIO
GT5 -- AXLE REAR, 4.10 RATIO
GU4 -- AXLE REAR, 3.08 RATIO
GU5 -- AXLE REAR, 3.23 RATIO
GU6 -- AXLE REAR, 3.42 RATIO
G80 -- AXLE REAR, LIMITED SLIP (POSITRACTION)
HC4 -- AXLE REAR, 4.56 RATIO
#7
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Car: 1990 Formula Firebird
Engine: 305 TBI (LO3)
Transmission: WC T-5 out of an 88 T/A
Axle/Gears: 10 bolt, 3.42 & Torsen Posi
Re: 6 lug square body?
you could prolly just swap your 5 lug axles into that housing to make it work
the RPO codes are all the same in regards to gear ratios, no matter if it was in a truck, wagon or corvette.
So look at the rpo codes and start googling them. Here is a quick list I found on fullsizechevy.com
GT4 -- AXLE REAR, 3.73 RATIO
GT5 -- AXLE REAR, 4.10 RATIO
GU4 -- AXLE REAR, 3.08 RATIO
GU5 -- AXLE REAR, 3.23 RATIO
GU6 -- AXLE REAR, 3.42 RATIO
G80 -- AXLE REAR, LIMITED SLIP (POSITRACTION)
HC4 -- AXLE REAR, 4.56 RATIO
the RPO codes are all the same in regards to gear ratios, no matter if it was in a truck, wagon or corvette.
So look at the rpo codes and start googling them. Here is a quick list I found on fullsizechevy.com
GT4 -- AXLE REAR, 3.73 RATIO
GT5 -- AXLE REAR, 4.10 RATIO
GU4 -- AXLE REAR, 3.08 RATIO
GU5 -- AXLE REAR, 3.23 RATIO
GU6 -- AXLE REAR, 3.42 RATIO
G80 -- AXLE REAR, LIMITED SLIP (POSITRACTION)
HC4 -- AXLE REAR, 4.56 RATIO
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#8
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Car: 1990 c1500
Engine: 357 chevy tbi
Transmission: Built 700r4
Axle/Gears: 3.42
Re: 6 lug square body?
Well the truck looks stock and the owners told me theres never neen any major work done too it so i expect the rearend to be untouched.
#9
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Car: 1990 c1500
Engine: 357 chevy tbi
Transmission: Built 700r4
Axle/Gears: 3.42
Re: 6 lug square body?
you could prolly just swap your 5 lug axles into that housing to make it work
the RPO codes are all the same in regards to gear ratios, no matter if it was in a truck, wagon or corvette.
So look at the rpo codes and start googling them. Here is a quick list I found on fullsizechevy.com
GT4 -- AXLE REAR, 3.73 RATIO
GT5 -- AXLE REAR, 4.10 RATIO
GU4 -- AXLE REAR, 3.08 RATIO
GU5 -- AXLE REAR, 3.23 RATIO
GU6 -- AXLE REAR, 3.42 RATIO
G80 -- AXLE REAR, LIMITED SLIP (POSITRACTION)
HC4 -- AXLE REAR, 4.56 RATIO
the RPO codes are all the same in regards to gear ratios, no matter if it was in a truck, wagon or corvette.
So look at the rpo codes and start googling them. Here is a quick list I found on fullsizechevy.com
GT4 -- AXLE REAR, 3.73 RATIO
GT5 -- AXLE REAR, 4.10 RATIO
GU4 -- AXLE REAR, 3.08 RATIO
GU5 -- AXLE REAR, 3.23 RATIO
GU6 -- AXLE REAR, 3.42 RATIO
G80 -- AXLE REAR, LIMITED SLIP (POSITRACTION)
HC4 -- AXLE REAR, 4.56 RATIO
#10
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Car: 91 Firebird
Engine: 6.0
Transmission: T56
Axle/Gears: 3.73
Re: 6 lug square body?
You *might* get away with that.....
but you would have to pull the axles to find out. At some point, GM switched from 26 spline axles to 28 spline, which I *think* was 87/88 in the fbody. Not certain about the trucks though
and yes, someone could have swapped the rear. Knowing the codes is just some knowledge. If you walk up and it has a code for a non posi 2.73 rear, I would walk away.....
but you would have to pull the axles to find out. At some point, GM switched from 26 spline axles to 28 spline, which I *think* was 87/88 in the fbody. Not certain about the trucks though
and yes, someone could have swapped the rear. Knowing the codes is just some knowledge. If you walk up and it has a code for a non posi 2.73 rear, I would walk away.....
#11
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Car: 1990 c1500
Engine: 357 chevy tbi
Transmission: Built 700r4
Axle/Gears: 3.42
Re: 6 lug square body?
You *might* get away with that.....
but you would have to pull the axles to find out. At some point, GM switched from 26 spline axles to 28 spline, which I *think* was 87/88 in the fbody. Not certain about the trucks though
and yes, someone could have swapped the rear. Knowing the codes is just some knowledge. If you walk up and it has a code for a non posi 2.73 rear, I would walk away.....
but you would have to pull the axles to find out. At some point, GM switched from 26 spline axles to 28 spline, which I *think* was 87/88 in the fbody. Not certain about the trucks though
and yes, someone could have swapped the rear. Knowing the codes is just some knowledge. If you walk up and it has a code for a non posi 2.73 rear, I would walk away.....
#12
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Car: 1990 Formula Firebird
Engine: 305 TBI (LO3)
Transmission: WC T-5 out of an 88 T/A
Axle/Gears: 10 bolt, 3.42 & Torsen Posi
Re: 6 lug square body?
You could try to look up the VIN, that would get you the RPO codes.
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