1990 K5 Blazer Axle Swap I need Some Help

[jws789]

I picked up a 1990 k5 4x4 Auto trans as a project upon getting it running I found out that the rear is blown beyond repair. I started to look for a new rear and found out I have 3.42 gears and no one really has them. I found a Set of 3.73 axles cheap from the same year truck am i able to swap them both without issue? Like do i need to do anything with the TCase ect?
Any help much appreciated this is my first blazer father had one growing up.

 

[fourwheelerjeff]

I picked up a 1990 k5 4x4
I found a Set of 3.73 axles cheap from the same year truck

when you say same year truck; do you mean another Blazer like you have? or a pickup of that year model? the pickup axles are not a bolt in. if they are from a Blazer or Suburban they would.

 

[jws789]

when you say truck; do you mean another Blazer like you have? or a pickup of that year model? the pickup axles are not a bolt in. if they are from a Blazer or Suburban they would.

Its another k5 blazer same year also am I correct that the 3.73 gears are better?

 

[6872xtc]

Its another k5 blazer same year also am I correct that the 3.73 gears are better?

Yes, definitely better in my experience.
I had 4:10 gears in my '90, with 33" tires and was very happy with it. I live at about 5000' elevation and the engine was high mileage, which makes a difference too.

 

[jws789]

Just got a new set of axles installed we all know every signle brake line fell apart. Does anyone know what size line this uses? It looks like smaller line and a really thick line comming off master cylinder.

 

[Wes Harden]

I Would love to say it's such and such size, but it could be several sizes and could be metric.
Are you going to delete the abs? I would encourage abs delete.
Take a look at Inline Tube. They should have the complete set

 

[ZooMad75]

Hardlines or soft hoses? Should be able to get stock replacements pretty easy.

 

[willysmn]

when you say same year truck; do you mean another Blazer like you have? or a pickup of that year model? the pickup axles are not a bolt in. if they are from a Blazer or Suburban they would.

what is different on pu axles?
thanks

 

[kennyw]

what is different on pu axles?
thanks

Nothing if the donor is a 1/2 ton or 3/4 ton squarebody. 1 tons have different spacing on the rear spring and shock mounts. The GMT400 pickup is also completely different spring pads and shock mounts and overlapped body styles in 1988-91.

 

[fourwheelerjeff]

I picked up a 1990 k5 4x4 Auto trans as a project upon getting it running
I found a Set of 3.73 axles cheap from the same year truck am i able to swap them both without issue?

what is different on pu axles?
thanks

Nothing if the donor is a 1/2 ton or 3/4 ton squarebody. 1 tons have different spacing on the rear spring and shock mounts. The GMT400 pickup is also completely different spring pads and shock mounts and overlapped body styles in 1988-91.

my answer was based on the fact that he has a 1990 K5 and says he found a set from the same year truck, meaning 1990. as @kennyw said; if they are from a GMT400 it will be different.

 

[Blue85]

Like do i need to do anything with the TCase ect?

The speedometer will be off. A 1990 should have the DRAC module behind the cluster. It is calibrated by soldering jumpers. Some people choose to install a DIP switch instead. https://harristuning.com/Tbi/vssb-drac-calibration/

 

[jws789]

The speedometer will be off. A 1990 should have the DRAC module behind the cluster. It is calibrated by soldering jumpers. Some people choose to install a DIP switch instead. https://harristuning.com/Tbi/vssb-drac-calibration/

Ok thanks

 

[jws789]

my answer was based on the fact that he has a 1990 K5 and says he found a set from the same year truck, meaning 1990. as @kennyw said; if they are from a GMT400 it will be different.

Yea they came off of another k5 blazer same year honestly it was better then mine shame he cut it up.

 

[6872xtc]

Yea they came off of another k5 blazer same year honestly it was better then mine shame he cut it up.

That happens and HAS happened more often than we realize or care to know.
At least you got some parts.

 

[jws789]

Got her running and sorta driving now was able to get it off my trailer finally ahaha. Where is the best place to buy body panels for these trucks? so far It does not look like they sell a full floor pan I am going to make a new thread with a ton of picture soon.