Wanting to Buy a GMT800 Rear End

[98chevy2500SS]

Hey guys,

I am on the hunt for a GMT800 rear end out of a 8.1 Vortec or a 6.6 Duramax.

Found one here: https://desmoines.craigslist.org/pts/d/parting-out-01-chevy-2500-hd/6647629458.html

Was wondering if $750 was much for a rear end of this size? Do the 99-02 rear ends have discs? And is this 11.5" full floater right?

 

[CarolinaOBS]

What is your motive for swapping to a gmt800 axle. Disc brakes?

I believe that axle does come with disc brakes, if in doubt go check it out I guess. You would have to re weld spring perches on it because I think the spring width is different between gmt400 and gmt800. It should be a 11.5” ff.

Just imo a full float 14 bolt is PLEANTY strong and disc brake swap kits can be had for $300 on eBay. Not to mention the axles are a dime a dozen.

 

[df2x4]

Just imo a full float 14 bolt is PLEANTY strong and disc brake swap kits can be had for $300 on eBay. Not to mention the axles are a dime a dozen.

My thoughts exactly. Sticking to GMT400 axles would save you a lot of fabrication work.

 

[Mike350AMF]

I grabbed an 11.5 FF out of an 03 Duramax. It has disc brakes. $600. It is going in an 99 Suburban 6.5 with an NV4500. Yukon 4.56 with a grizzly locker. I can post measurements of spring perches and shock mounts if you would like once its completed next month.
I think its well worth the effort so far.

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[98chevy2500SS]

Motive is for strength, disc brakes, the width, and just to brag that I have a big rear end in my truck, lol. Would rather use a GMT800 rear end because the widths are closer than the 400's are, so I wouldn't have to use spacers in rear anymore. I don't know, it's just been an idea I have been throwing around in my head, need to get new bumpers for my truck first.

 

[Pighuntin]

When going from drum brakes to disc brakes, you will need to get a master cylinder to match otherwise you will have a weak brake pedal. Just a FYI.

 

[98chevy2500SS]

Yeah that's right, I would have to get a master cylinder to match, dang, maybe this swap would be more than I thought was involved. I guess I've got some thinking to do.

Thanks for all the responses! I really appreciated the feedback.

 

[98chevy2500SS]

I grabbed an 11.5 FF out of an 03 Duramax. It has disc brakes. $600. It is going in an 99 Suburban 6.5 with an NV4500. Yukon 4.56 with a grizzly locker. I can post measurements of spring perches and shock mounts if you would like once its completed next month.
I think its well worth the effort so far.

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You'll have to let me know on the progress with that swap!

 

[Pighuntin]

The master is no big deal. A little bit of research and you can find the right master. I would find and test fit a master from the truck you are pulling the rear axle from. That would have all the right specs for the brakes. The hardest thing from my perspective is finding a place that will help you locate brake line fitting adapters to go from the new master to your existing lines. Or you could flare your own lines depending on your skill and tools.

The swap isnt gonna be as bad as you think its gonna be. It may cost you a bit more if you need say a new vacuum brake booster or hydroboost unit to match the new master.

 

[CarolinaOBS]

When going from drum brakes to disc brakes, you will need to get a master cylinder to match otherwise you will have a weak brake pedal. Just a FYI.

Yeah that's right, I would have to get a master cylinder to match, dang, maybe this swap would be more than I thought was involved. I guess I've got some thinking to do.

Thanks for all the responses! I really appreciated the feedback.

Just IMO. Install a proportioning valve and use factory MC. Easy fix.