Converting 1988 2500 6 lug to 8 lug 2wd

[Insert Quarter]

For what you're doing, I think you just need upper control arms, spindles, and brakes. The lower control arms I believe are the same. GM added ABS tone rings on the front rotors in the later years. I attached pages from the parts book.
It's a good idea to measure the spindle for wear when you're looking for these.

The only differences I've noticed so far on the 8600 frames (regular cab long beds) aside from the actual suspension components are:
1) The front fuel tank support (one style is visible in the gap between the cab and the bed and has a carrier bearing bolted to it and can't find replacements for these, the other one bolts in the same holes on the frame but is swept back slightly under the truck bed, Dorman makes a replacement for these)
2) The rear leaf spring mounts are different. The 8600 8-lug 3/4 ton uses the 4WD rear leaf spring mount and has a second bracket that is a 90 degree support from the spring bolt hole on the back side of the mount to the frame.

Rear Leaf Spring - Rear Hanger - '89 C2500 8,600 GVW

Just came across this and wanted to share. I'll lead with: Dorman 722-008 is the correct rear leaf spring rear hanger for an '89 C2500 8,600 GVW Wanted to lower the rear to level it out a bit before adding Air Lift load leveler bags. I originally ordered the Dorman 722-007 hanger but it is...

www.gmt400.com

 

[Lu Blunt]

What about changing the rear axle from 8 lug to 6 lug?

 

[Jackaru]

I’m not saying the 8 lug front end parts aren’t more stout, of course they are, but you’ll still have the 7200 GVWR frame. Again, not sure about 2wd, but couldn’t you just add beefier springs up front. I think your brakes would be fine.

OMG. why can't one just answer technical questions without projecting their own priorities. FoxNotch didn't say he wanted to give the truck a 8600lb GVWR, he said the front end is already shot, they put a heavier engine in, and and the rear is already a 14 bolt FF. they have obviously already modded their toy quite a bit, so It makes perfect sense. Who wants to drive around with 8 lugs on the back and 6 up front? Even if tire sizes match, Two sets of different rims? Replacing the front end, he'll have improved braking and heavier springs, both of which will offset the extra weight of the engine. He may not have a full 8600lb GVWR, but He will have a more robust front end with heavier springs, brakes and bearings. He already changed to an indestructable rear. The frame is not going to collapse.

 

[Supercharged111]

OMG. why can't one just answer technical questions without projecting their own priorities. FoxNotch didn't say he wanted to give the truck a 8600lb GVWR, he said the front end is already shot, they put a heavier engine in, and and the rear is already a 14 bolt FF. they have obviously already modded their toy quite a bit, so It makes perfect sense. Who wants to drive around with 8 lugs on the back and 6 up front? Even if tire sizes match, Two sets of different rims? Replacing the front end, he'll have improved braking and heavier springs, both of which will offset the extra weight of the engine. He may not have a full 8600lb GVWR, but He will have a more robust front end with heavier springs, brakes and bearings. He already changed to an indestructable rear. The frame is not going to collapse.

Irrelevant as the 2 front ends and frames are completely different. Easiest way out would be if somebody made a steel adapter spacer. Add heavier torsion bars if you like. Brake rotor diameter differences are negligible. To do it proper would either require a frame splice or frame swap.

 

[Insert Quarter]

Irrelevant as the 2 front ends and frames are completely different. Easiest way out would be if somebody made a steel adapter spacer. Add heavier torsion bars if you like. Brake rotor diameter differences are negligible. To do it proper would either require a frame splice or frame swap.

Just curious, how are the frames different? The only two differences I've noticed are listed in post #11. FYI - OP has a 2wd so it's coil springs in the front.

 

[Supercharged111]

Just curious, how are the frames different? The only two differences I've noticed are listed in post #11. FYI - OP has a 2wd so it's coil springs in the front.

Ahh, NM missed that part. What I said applies to 4wd. You 2wd guys have it easy!

 

[FoxNotch]

For what you're doing, I think you just need upper control arms, spindles, and brakes. The lower control arms I believe are the same. GM added ABS tone rings on the front rotors in the later years. I attached pages from the parts book.
It's a good idea to measure the spindle for wear when you're looking for these.

The only differences I've noticed so far on the 8600 frames (regular cab long beds) aside from the

For what you're doing, I think you just need upper control arms, spindles, and brakes. The lower control arms I believe are the same. GM added ABS tone rings on the front rotors in the later years. I attached pages from the parts book.
It's a good idea to measure the spindle for wear when you're looking for these.

Thanks for all that info.
I think I done good. Picked up a full front end from a 98 2500 this weekend. A little rusty, but only 37k miles and new rotors/pads and shocks
And a full set of wheels/tires in great shape. 500 bucks.
Seems like njdot put a bunch of work into the truck and then sent it to auction.
I'll report back how everything switches over.
Matt

 

[Caman96]

but couldn’t you just add beefier springs up front.

and heavier springs, both of which will offset the extra weight of the engine.

Seems I already posted that. Does that mean you’re projecting now? OMG!!!

 

[Supercharged111]

Thanks for all that info.
I think I done good. Picked up a full front end from a 98 2500 this weekend. A little rusty, but only 37k miles and new rotors/pads and shocks
And a full set of wheels/tires in great shape. 500 bucks.
Seems like njdot put a bunch of work into the truck and then sent it to auction.
I'll report back how everything switches over.
Matt

Good haul, now get to work!

Also we need a smilie who's cracking a whip.

 

[Caman96]

Good haul, now get to work!

Also we need a smilie who's cracking a whip.

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