1989 Suburban 2500 ???'s

Edited: 6/15/2009 1:28:23 PM by Kronicles

So I picked up this Burban last week and I'm contemplating what all I want to do with it. Big problem I'm seeing is that since it's a 3/4 ton I have an 8 lug pattern vice the normal 6 lug, can I change this? I also have a big ass 454 in this beast, unsure of the tranny as of yet, but I'm thinking of finding a newer drivetrain for this bad boy. If I do this will I have to change out my rear axle as well? I'm thinking of just finding a 350 with a 4 gear tranny vice the 3 gear that's in it now. How hard will this be, are these fairly easy to accomplish if I try and go this route? Lastly is the interior, can I take a dash from say a 60's or 70's chevy and swap it in? The seats are decent now, but I want to upgrade to something a little more comfortable like some of the 90's models I've been in in the past. Question here is what year 9? can I go with and it be simple swap without having to do a whole new set of holes.
 
So maybe that wasn't lastly, the suspension is now the ??? I want to keep it simple, but also give it decent drop. I'm thinking a 3/5 but haven't been able to find a kit anywhere just yet. Also what is the best way to go about this, springs, drop spindles, drop shackles, etc?
 
I know this is a lot of ?'s but honestly this is my first real truck project and I want to make sure I do it right. Thanks for any insight or advice ahead of time!!!

as far as the 3 gears to 4 gears question, you would need to swap gears in the rear or put a different rearend all together in it (which could solve the 8 to 6 lug problem to if you just switched spindles to a 1500 spindle and get rotors for it cause i know that some chevy spindles will switch cause they use the same taper on the balljoints) cause in the 3 speed you have atleast a 3.73 or higher (maybe 4.11 or even 4.56 if its a 3/4 ton) plus all smallblock chevy and 90 degree six cylinders have the same motor mounts but the sixes are shorter so watch out. hope this helps

k, so swap in a 700r4, swap out the rearend and a small block will bolt right in where the big block was? Somehow that last part don't sound right?

yeah you can change the front rotors they are the same with the five lug rotors.same bearings and all as for the rear end just get one from the junk yard.the spindles are the same i have done this when i made my dually it use to be a 1500 chevy. just as long as its a lite duty 3/4 ton which i think it is.so you do not have to change out the spindles just the rotors that is it.

in time the spindles will be changed out for a set to lower it of course, but wouldn't I have to go with 6 lug to support the body? according to the smog I got Sat. it weighs 8600+ supposedly all that's available is a 2" drop spring for the front and 2" drop shackles for the rear, since it's a suburban, not a regular C/K 2500. no flip kit supposedly available which I find hard to believe, with people dropping duallies all the time there has to be more available!! as far as parts, I know junkyrads are great, plus seen a few places on craigslist that carry all sorts of parts

bump... still need some help on this please, I know some of you know a lot of these answers. I've had 2 answered so far.

supposedly there is a 4/5 drop kit available. anyone have some insight on that? who makes it, where can I get it?

Your truck chassis is designed around that package.To answer your question: 1. Your truck probably has a 3 speed 400 Turbo in it. You can swap a vaccum modulated 700R4 with no problems. Kick down linkages are the same. You can get a later model electric 700R4 but you will need to get a torque convertor lockup harness. It will bolt to the rear end just fine. Now, you would need to know the gear ratio in the rear end and calculate that to the new final drive ratio in the trans to see if adjustments are needed to the ring and pinion, if you kept the 454 and 3/4 driveline. 2. The weight rating of the truck is strictly limited to payload rating. It sucks that you do have inspection so I do not know the laws. But, to change it to a 1500 suspension. you would need a 1/2 ton rear differential, spindles, rotors, calipers. change the ball joints in your control arms to a 1500. That truck has a set of big block springs in the front. if you keep the 454 you will need to keep them. Rear spings should bolt to a GM 8.5 with no problem 3. Seats. Actually a set of buckets from a 95-99 will bolt in on the driver side with no problems. Pass side will have to drill 2 holes. This was my expirence with a K5 Blazer.  Hope this helps. 

---------------------------------------------Originally posted by MaterYour truck chassis is designed around that package.To answer your question: 1. Your truck probably has a 3 speed 400 Turbo in it. You can swap a vaccum modulated 700R4 with no problems. Kick down linkages are the same. You can get a later model electric 700R4 but you will need to get a torque convertor lockup harness. It will bolt to the rear end just fine. Now, you would need to know the gear ratio in the rear end and calculate that to the new final drive ratio in the trans to see if adjustments are needed to the ring and pinion, if you kept the 454 and 3/4 driveline. 2. The weight rating of the truck is strictly limited to payload rating. It sucks that you do have inspection so I do not know the laws. But, to change it to a 1500 suspension. you would need a 1/2 ton rear differential, spindles, rotors, calipers. change the ball joints in your control arms to a 1500. That truck has a set of big block springs in the front. if you keep the 454 you will need to keep them. Rear spings should bolt to a GM 8.5 with no problem 3. Seats. Actually a set of buckets from a 95-99 will bolt in on the driver side with no problems. Pass side will have to drill 2 holes. This was my expirence with a K5 Blazer.  Hope this helps. ---------------------------------------------Outstanding input and information, thank you so much. I will look into inspection being an issue as far as the changes. The seats, so awesome to get that info, going to craigslist now!  

Next question... The Burban is stalling out on me from time to time and starting again if I just let it sit for anywhere between 10 mins and 1 hr. Talked to a buddy said it could very well be the fuel pump. Another guy on a different forum said it's not that alternator as I first suspected or else I would be swapping batteries or having to get a jump on the reg. Well I'll be changing out the fuel filter as I did the tune up and a few other things since I bought this beast.  So the question is: will a fuel pump from a 89 reg cab pick-up with the same engine (454) as the burban, will it work in the suburban?