GMT 400 front end rebuild + lift kit

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df2x4

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That's awesome thanks. Kind of wierd though. I thought the gov kicked in on 97/98mph

It does, unless you disable it in the tune. :secret:

As long as the speed rating of the tires exceeds the max operating speed of the vehicle, you're fine. You just don't want to put a 90MPH rated tire on a supercar or something.
 

SUBURBAN5

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It does, unless you disable it in the tune. :secret:

As long as the speed rating of the tires exceeds the max operating speed of the vehicle, you're fine. You just don't want to put a 90MPH rated tire on a supercar or something.

Learned something new lol. These are rated for 118mph apparently:) sounds like after I get my 383 I need to get a tune:)
 

Vikingdude

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So much good info in this thread! Having recently redone my steering box, tie rods, pitman arm, and idler/bracket this has given me a clear road map of what else to do to get my truck up to *****.
 

noabarron3

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So much good info in this thread! Having recently redone my steering box, tie rods, pitman arm, and idler/bracket this has given me a clear road map of what else to do to get my truck up to *****.
Glad to hear it! Good luck!
 

Zseventy-one

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Thanks.
So I went with the RCX 6”, 17” Mickey Thompson classic II, I had the original Mickey Thompson’s before with no lift, and 35” x 12.5 Cooper tires.
My kit came with and add a leaf and blocks. I think that may have been an error because when I put them both on, the truck was 2-3” higher in the back. Almost like stock, maybe worse. So I ordered 2” smaller blocks and it’s close now. Still. At be a 1/2” to an inch higher in the back but for now it’s good. I’ll see if it settles a little. I may even put a couple hundred pounds in the bed. I had some wood back there for a week a couple months ago and it made it ride so nice.
My steering is pretty tight but I was driving it last night and it did seam to wonder just a little. I never know if that’s just the age of the truck or I should update the steering box. I drive my 17’ gmc Duramax more and so I try not to compare the two trucks but I always think my ‘89 should drive like my ‘17. Lol.


Truck looks great! Is that a custom grill guard/bumper combo? Haven't seen any that look like that but love the clean and mean tubular look it has.
 

Matt84

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Just came across this and wonder how the project is going.
I rebuilt the front end and lifted my 89’ in March.
There’s a lot of good advise here. I did mine in my garage on jack stands. I’ve done a few trucks and a Jeep now and it doesn’t seam to get any easier.
But overall it’s worth it just for the knowledge. It took me about two weeks to finish mine front and rear. Partly because I forgot to order a couple of bushings I wanted to replace.
For anyone looking to do this I would suggest a week before you start to go around and spray everything you see with a thread and nut on it with some sort of penetrate. I live in the desert of Ca and with all the dirt and mud from 30 years it was fun to get some stuff off. Especially the torsion bars. I couldn’t imagine a place where salt and rust is a problem.
But rebuilding the front end was the best thing. It’s so much tighter now. I didn’t realize how sloppy it was.

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Hey there. I have some questions for you. How many inches is your lift kit? The reason I ask is because I have a 94 Chevy with a 6” lift kit. I rebuilt the truck and swapped the drivetrain and dashfrom a 98 5.7. The only thing I’m stuck on is that I didnt have the sway bar end links on the truck when I got it. I purchased a pair but there is no way I can get them in since they appear much longer than the stock ones and I can’t find any the same size as the old ones. Thanks in advance. Pics for the looking
 

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