Tech: 88GMCtruck's Budget Solid Axle Swap Build

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88GMCtruck

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Since my SAS was completed before me coming to GMT400 and I keep receiving questions on other forums regarding it, I have compiled a condensed thread of the SAS of my 88 Sierra. In the summer of 2008, I began collecting parts and once I had my new truck (the 02) I decided to replace the inadequate IFS in my 88 Sierra and install a Dana 44 Solid Axle. With the help of my Dad, the project took 3 weeks to finish. The goal is to keep it all GM, run 35's, and make it look like it rolled off the assembly line with the solid axle. I also wanted to keep the bill under $2,500 (excluding wheels/tires). The total cost was $2,700 for the lift, and $1,500 for wheels/tires.

Some random “before” pictures, since you haven’t seen them.
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My intent was to basically make the truck more capable and stronger than it was with IFS. I'm not going to wheel the living pee out of it which is why I'm only going with a D44, and I don't need it to be huge by any means. Honestly the choice of 35's basically boils down to the fact that I'm going to still be driving this regularly and large tires cost big bucks!

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The Plan:

Front Axle: Dana 44 from 1977 GMC K15, 3.73s, trussed, flat top knuckles, HD shafts, spicer joints, Warn Premium hubs.
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Rear Axle: 14 Bolt SF from 1993 C2500, 3.73s, G80

Transfer Case: Passenger drop NP241-C from a 1990 1500 Suburban
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Steering: DT machine steering arms, Full crossover and hi-steer, Superlift 1104 Pitman
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Front Suspension: Custom front spring mounts, 1977 GMC rear spring mounts, 52" springs & shackles with overloads removed from the rear of the 1977

Rear Suspension: ORD shacke flip, 4" block, Stock 64" springs
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Brakes: Stock 1977 front discs, Stock 1993 rear drums, teflon/kevlar/stainless lines from ORD
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Shocks: Rancho RS5000

315/75R16 Mickey Thompson MTZ
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16x8 Raceline Renegade 6
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7-21-2008
Out goes the IFS:
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Inadequate parts:
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I started removing the transfercase, and started mounting the front springs.

52" spring with overloads removed
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Front Spring mount built and welded
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Spring hanging from front at approx. unloaded height.
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7-24-2008
Started grinding the remaining metal off from the old IFS brackets. We have added additional to the inside of the frame under the cab and one spring is fully in place
 

88GMCtruck

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7-27-2008
The transfercase is in waiting for a new crossmember and shift linkage. We removed most of the old IFS crossmember and 1/4" plated it, and made a new set of spring hangers 1" forward and 1" lower than the previous also 1/4". The axle was fully stripped and painted.

The springs are a custom pack made from two sets of 5 leaf 1/2ton 73-87 Chevy truck rear packs. Two shorter leaves were made from one pack and added. All were painted individually as well. They were installed with energy suspension bushings.

We have everything tacked on and she is now sitting! These tires are only 29" but after measuring I think the truck is sitting at 7-8" of lift.

We are going to add an additional crossmember between the front spring perches and build my steering soon. I have all my parts now except shocks.

She sits on her new suspension!
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Front 1/4" spring hangers, boxed
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Rear spring hangers from 77 GMC (they will be fully welded soon)
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Flat plated crossmember
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Custom 7-leaf pack
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New t-case installed, waiting for custom crossmember
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7-31-2008
-Crossover steering
-Drop transmission crossmember finished
-New front crossmember and shackle mounts finished (needs welded in)
-Figured out shocks and mounts
-Ground CV driveline to have enough workable angle and not bind

8-2-2008
Front frame ground clean
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New crossmember and shackle mounts
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Front with crossover & driveline
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New trans crossmember
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Ground driveline
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Crossover
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Truck sitting on a set of 32`s
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All that is left up front is brake lines, shocks, swaybar and steering stabilizer, as well as the rear lift.
 

88GMCtruck

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8-3-2008
Here is some more eye candy.

Sitting with the "Cali" lean - Fronts back together!
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Brake lines
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Steering Stabilizer
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Started the rear lift
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Shackle bolts aren’t tough enough, replacing with grade 8 (Note: ORD has since changed their bolts from grade 5 to grade 8)
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I should have the rear pretty much finished up tonight and then it's just little things like making shock mounts up front. I only have to order shocks, wheels and tires as of now. She is nearing completion!!!

8-4-2008
Well as of last night, the rear lift is installed. I ended up using the shackle flip and 4.5" blocks, and everything went together well. The rear is sitting about 3/4" taller than the front, just how I want it.

We also set the pinion angle within 1/2 degree of the transfercase. Now all I need is a 2" longer driveline, junkyard here I come!

I just ordered Rancho RS5000 shocks, 16x8 Renegade Raceline 6 wheels and 315/75R16 Mickey Thompson MTZ tires. Shocks, tires and wheels = ~$1,700. Building a solid axle GMC = PRICELESS!!!

8-7-2008
The anti-swaybar is FINALLY done. I personally think it was the single most time consuming piece on the truck, after fabricating it, mounting it to clear the tierod and pitman arm, brake lines, etc, and making the disconnect for it.

The new shifter linkage is also done. I kept the stock floor shift on the driver`s side and created a linkage to the passenger side. It is a very crazy looking piece as well. The shift pattern on the P-drop 241 is opposite the stock case. From top to bottom, stock was 4L-N-2H-4H and is now 4H-2H-N-4L. That will take some time to get used to!

Rear 34" Rancho 5000 shocks are mounted. Front mounts should be fabricated and shocks mounted tomorrow.

I bought a new driveline for the rear. I found that the 99-07c regular cabs had a 2" longer driveline than my 88, which is perfect for the lift. Today it will get new u-joints.

The only other thing left is to re-do the exhaust and top off fluids.

8-9-2008
Here are the pictures from a few nights ago.

Shift linkage
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Re-routed transfer case harness
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New 2-hi shift position
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New rear driveline from a 2002 Reg. cab (needs paint)
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Rear shocks and remounted breather
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ORD Shackle flip
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Front shocks
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Everything is about done now!
 

88GMCtruck

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8-10-2008
Well, it's 99% done. As of now I just have a few small things to do, such as cut and install the new air-dam, re-paint the rest of the frame black, build a spare tire mount, etc.

I drove it and it drives great. Brakes are much better over stock, nice and firm. The anti-sway bar works great, truck has very minimal body roll even cornering hard at 40. It rides just as good as stock too. All in all I'm very pleased with the way it handles.

Ok, now it's time for your favorite thing.... more pictures.

Washed up in the driveway
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Initial testing, Flexing on some gravel
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Second test, Flexing at the motocross track
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With the new wheels and tires.
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An interesting comparison next to my old roommate’s 95 K1500 6.5L
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Overall, the project took 3 weeks and cost $4,200. I honestly can say it was one of the best choices I have made and do not regret spending any of the time, money or effort on this. I had a great time working with my Dad, and now have a truck that is not only ridiculously capable, but even more practical for my life. The truck is still daily driven, handles very well, and I still get about 16mpg on the highway. I take this truck through everything possible and it just takes it. If anyone has any questions, let me know. :D
 
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JAYB1RD

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Nice consolidation of info and pics, now I have a reference thread to bother you on HAHA

Are your 52s up front just stock without overloads? Did you put in an AAL or anything else? I guess I thought the brackets added 3-4" of lift if used with stock springs and if you want more you need to get some lift springs.
 

88GMCtruck

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Ah, well there is a like 7 page thread of it over on FSC, but at least you found one of them.

They are stock 73-87 rear 52's. I ended up using two 5-leaf 1/2ton packs (they also come in 4,6,7 and 9 leaf packs) and I removed the overload, and added two shorter leaves to make a 7-leaf pack. With my brackets where they are and these 7-leaf springs, I'm sitting at a good 8" up front. When your doing a custom SAS the brackets really have less to do with the amount of lift because you can position them more or less where you need. Most kits add 4" when using stock 73-87 front springs.
 

JAYB1RD

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Ya I know, that's in my bookmarks too! But when I'm on the shop floor with a minute or two to kill I use my phone to research truck stuff on. This is a nice smallish sized resource page to load and not have to remember which of your pictures is on which page LOL

Thanks for the leaf info. I haven't decided for sure yet if I'll build my own brackets or buy some, but I do know I want to run 52s. I like ORUs kit, a bit spendy but it does have some knick knacks that I would otherwise be sourcing on my own with other options.
 
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very nice! my 88 has a sas but 44s, love the stepside, im looking to get that bed on mine
 
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