Astro AWD knuckle swap?

4.3CPI

New member
Will the AWD Astro steering knuckle swap onto an AWD or 4x4 S-series?

Reason being is that I want to upgrade to the 8.5 inch rear diff, but want to find some way to keep front/rear bolt pattern the same without re drilling every time I need rotors. I would prefer the 5 on 5" pattern vs the 6 lug of the AWD astro due to rim availability. I don't believe GM made any 5 on 5" front hubs or compound rotors.

Drilling the Astro front hubs for the 5 on 5", and redrilling the rotors also would probably be my best bet. I'm betting that the AWD astro hubs have the correct diameter center pilot to match an Impala SS 8.5" rear.

My plans are;
94-96 Impala disc rear, with 3.42 gear swap (same width as front axle)
Astro front knuckles
Astro hydroboost
AWD T-case

I'm planning on running an Eaton M90 blower on my non sy/ty 4.3, or running a Weiand blower on the 327 I have on the engine stand.
 

mattw

Active member
Re: Astro AWD knuckle swap?

4.3CPI said:
Will the AWD Astro steering knuckle swap onto an AWD or 4x4 S-series?

Reason being is that I want to upgrade to the 8.5 inch rear diff, but want to find some way to keep front/rear bolt pattern the same without re drilling every time I need rotors. I would prefer the 5 on 5" pattern vs the 6 lug of the AWD astro due to rim availability. I don't believe GM made any 5 on 5" front hubs or compound rotors.

Drilling the Astro front hubs for the 5 on 5", and redrilling the rotors also would probably be my best bet. I'm betting that the AWD astro hubs have the correct diameter center pilot to match an Impala SS 8.5" rear.

My plans are;
94-96 Impala disc rear, with 3.42 gear swap (same width as front axle)
Astro front knuckles
Astro hydroboost
AWD T-case

I'm planning on running an Eaton M90 blower on my non sy/ty 4.3, or running a Weiand blower on the 327 I have on the engine stand.


What is a steering knuckle? Are you talking about the spindle? or bearing maybe? or half shaft?

I didn't knwo that the Impala rear is the same width as our front axle. Thats nice to know and sounds like a worthy upgrade.

Good luck,

-Matt
 

turbodog

Donating Member
Re: Astro AWD knuckle swap?

Steering knuckle is the correct GM term for what I believe you are referring to as 'spindle'. In a 2WD it includes a spindle. In the 4WD/AWD there is no 'spindle'. However, I have absolutely no idea if a Astro knuckle will come close to bolting in to a S-truck front end.
 

4.3CPI

New member
Re: Astro AWD knuckle swap?

Yes, the spindle/hub assembly.

I have a camaro disc axle in my truck now, and it's a 7.5" diff. It's howling badly. I hate these puny rears. As far as width, the camaro / firebird axles and the B body axles are the same width. The pre 91 caprices had the 7.5", unless it was a wagon, and the 91-96 caprice / impala had the 8.5". I guess the non-LT1 9C1 police package rears came with a 3.42. I suck at swapping gears and carriers. I've ruined too many sets.

Anyway, my tires stick out the same distance on all four corners, and all four wheels have the same backspacing and width.

It's not a plug and play, as you have to cut off whatever stock brackets are there, and weld on your original spring perches. That aside, a 7.5 to a 7.5 is basically a direct swap. The 8.5 would probably need a special U-joint.

As far as my original question, I guess I'll have to take a trip to the junkyard and try swapping it there to see about fitment.
 

jimhrabe

Donating Member
Re: Astro AWD knuckle swap?

Why not just get an 8.5 disc brake rearend out of an 5-speed extreme blazer?
 

4.3CPI

New member
Re: Astro AWD knuckle swap?

One thing I do like about my camaro rear is the width. The truck handles pretty good with it, and it looks cool with the tires balanced.
 
Top