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1998 k1500 hd with 6.5 into a 1989 k1500 4x4 350 gas

S

Shitbox_garage

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Hey guys i am swapping a 1998 6.5 diesel into my 1989 k1500 4x4 has the 350 gas in it. I have the whole truck but the 6.5 frame is totaly trashed what should i do for wiring and fuel, will the tank and everthing swap. The 6.5 runs what would i need to swap the harness from the 98 to my 89
 
I know nothing about what the wiring on a '89 is, but if you want to get rid of as much wiring as possible convert the '98 6.5 to a mechanical injection pump and manual wastegate turbo. Won't have to swap over the ECM at all. What transmission is involved? I don't know squat about automatics. Manual is fewer wires. Things cluster related I can't speak to, basic for fuel would be a lift pump and lift pump relay, manual glow plug switch. Welcome to TTS, fill out your sig with all the details of your rig/ project, it helps us make suggestions specific to your setup.
 
Welcome to the forum. if you are keeping the trans in the 89 and it's a non-electronic one, then yes do convert the 6.5 to a mechanical injection system, you'll be much happier. if you want to use the 4l80e that's in the 98, then you will need to ether keep the ecm and electronic injection or convert to mechanical on the engine and get you a stand alone trans controller kit with harness.

as for the fuel tank and lines, you can use the existing fuel tank but adapt the lines to at least 3.8" tubing for the supply and install a inline lift pump on the frame to supply between 8-14 psi fuel pressure to the injection pump. this is for both manual and electronic injection engines.

more knowledgeable folks will chime in shortly.
 
Welcome.
Everything will not just swap over. Either Custom brackets to mount the tank innthe other truck, or you need to add a second fuel line. Diesel has two lines that both HAVE TO be fully submerged.

Dash gauge will be a mess. If you are really good at fabrication you could make it work.

Making the wiring harness fit will not be easy- there is no kit to buy. Cut and extend where you need to, but my suggestion is leave the main harness from ecm to ds4 untouched if you have to keep the ds4

Other option:
The suggestions of swapping to db2 and loosing the ds4 along with turbo control is good, ditch the ecm as well. Then you can ditch the wire harness and just wire things in yourself from new. Buy aftermarket gauges instead of the factory.

Many many people try this and end up selling both trucks for parts for a couple hundred dollars at best. Many people think they can do this for $1,000 or under. Nope- People that have the skills and tools to do it never ask. Nothing personal, just saying.

Happy to help as you go through it if we can.
 
My two cents. Don't bother. WAY too much hassle, time and expense to do. If you really want to reuse the 6 5 drivetrain, you'd actually be better off finding a GMT-400 gasser with a blown motor/trans or no drivetrain in it and a good frame/body and swap into that. Everything would then be pretty much "bolt in" as far as fuel tank, ECM, dash, harnesses, etc.
 
Yeah, what @THEFERMANATOR was saying. Your 89 is a solid front axle, all sorts of MAJOR drivetrain differences that would require a different transfer case, new drive shafts, etc. You're still way ahead to find a good, used GMT-400 that is the same configuration (ie: Reg cab long bed or extended cab long bed, etc) as your current one and also 4x4 and swapping into that.
 
THEFERMANATOR said:
Couple of questions before anybody can give you accurate info. Are both trucks 4x4? Are they both the same cab & bed configurations? Just how in depth are you willing to get with this swap?
Click to expand...
Both are 4x4 the 6.5 is just smashed and one is an extended cab and my 89 is regular cab step side i was planning on keeping trans, tcase, and drive lines
 
MrMarty51 said:
The 89 K1500 is the same body style as the 98 and the 89 should still be IFS. 1987 was the last year for the solid axle and square body for the 1500 series.
Correct Me if I am wrong please.
Click to expand...
Yup, ALL 1500 pickups starting in 88 were gmt400 body styles, square body half ton trucks stopped in 87. SUV's stayed square body to 91 as well as the 4 door 3500 pickups.
 
Shitbox_garage said:
Both are 4x4 the 6.5 is just smashed and one is an extended cab and my 89 is regular cab step side i was planning on keeping trans, tcase, and drive lines
Click to expand...
If both trucks were extended cab short beds, then you could just swap the tanks. You can take the metal sender assembly out of the 98 diesel and put into your 89 tank, remove your fuel filter from the 89 and install the 6.5's lift pump. Your 89 will have the light duty front brakes though(1" thick rotors) where all 6.5l trucks got the 1.25" thick rotors. You can swap the spindles and such over to get the heavier brakes as the 88-91 standard cab light duty brakes were not the greatest, or swap to nbs brakes. The hydro-booster and brake pedal from the 98 should swap right into your 89. You may have to swap the radiator core support over to fit the larger radiator, or you may be able to make yours work with modifications. There was no 34" wide radiator core offered until 90 or 91, so I'm not sure if it will go into yours or not.

If you want AC you will have to have custom AC lines made. Up to 93 GM used sae fittings with R12 refrigerant, 94+ used metric for r134. Being an 89 yours has the early small condenser and the early AC control system with no manually selectable recirc mode. You can change the condenser, but your trouble comes in at the evap. The 98 hoses will only work with the 96+ accumulator, and the 96+ accumulator will not work with your 89 evap because of the thread change. You could pull the dash out and swap to the 94+ evap, but as far as I know it will not fit in the early evap housing(r134 evaps are thicker), and I don't believe your 89 control head will work correctly with a 98 evap housing(the doors changed iirc). So it's custom AC lines only.

Wiring is where things get tricky. You will essentially have to turn the 6.5l engine harness into a stand alone. The speedo should be able to work by running your transfer case speed sensor signal to both the cluster and the VSSB. 89 has the moonie gauges that have a built in DRAC in the cluster, the 6.5l has to have a VSSB to read the speed sensor and provide the neccesary speed signals.

You will have to do some work to make the 89's mechanical shift linkage work with the 4l80e trans. 98 used a cable shifter, so you will have to change the shift arm, most likely have to change the 4l80e's long shift shaft to a short one, and lengthen the shift rod. You can drill new holes in the 89's frame to move the trans crossmember back.

These are the major details that come to my mind at the moment, but I'm sure I'm overlooking quite a few. It's a doable project, but will be alot of work for all of the small details.
 
Sounds like this will be a fun project. post some photos of both rigs as they are and start your swap. we all love to see builds like this :) Maybe even make a build thread with lots of photos as you go along. we all can give you some good pointers. as for the drive line and trans. I don't know how stout a 700R4 is, but if you want the overdrive and TCC lockup and don't want to hassle too much with the electronics side of things, that trans might be an option while converting the engine to mechanical injection with a db2 pump. those can still be has 100% new and on the plus side of things with diesel prices the db2 can handle WMO and other darker colored diesel fuel without any issues. the ds4 on the other hand can't run black diesel and doesn't like red diesel due to the optic sensor in the IP.
 
THEFERMANATOR said:
If both trucks were extended cab short beds, then you could just swap the tanks. You can take the metal sender assembly out of the 98 diesel and put into your 89 tank, remove your fuel filter from the 89 and install the 6.5's lift pump. Your 89 will have the light duty front brakes though(1" thick rotors) where all 6.5l trucks got the 1.25" thick rotors. You can swap the spindles and such over to get the heavier brakes as the 88-91 standard cab light duty brakes were not the greatest, or swap to nbs brakes. The hydro-booster and brake pedal from the 98 should swap right into your 89. You may have to swap the radiator core support over to fit the larger radiator, or you may be able to make yours work with modifications. There was no 34" wide radiator core offered until 90 or 91, so I'm not sure if it will go into yours or not.

If you want AC you will have to have custom AC lines made. Up to 93 GM used sae fittings with R12 refrigerant, 94+ used metric for r134. Being an 89 yours has the early small condenser and the early AC control system with no manually selectable recirc mode. You can change the condenser, but your trouble comes in at the evap. The 98 hoses will only work with the 96+ accumulator, and the 96+ accumulator will not work with your 89 evap because of the thread change. You could pull the dash out and swap to the 94+ evap, but as far as I know it will not fit in the early evap housing(r134 evaps are thicker), and I don't believe your 89 control head will work correctly with a 98 evap housing(the doors changed iirc). So it's custom AC lines only.

Wiring is where things get tricky. You will essentially have to turn the 6.5l engine harness into a stand alone. The speedo should be able to work by running your transfer case speed sensor signal to both the cluster and the VSSB. 89 has the moonie gauges that have a built in DRAC in the cluster, the 6.5l has to have a VSSB to read the speed sensor and provide the neccesary speed signals.

You will have to do some work to make the 89's mechanical shift linkage work with the 4l80e trans. 98 used a cable shifter, so you will have to change the shift arm, most likely have to change the 4l80e's long shift shaft to a short one, and lengthen the shift rod. You can drill new holes in the 89's frame to move the trans crossmember back.

These are the major details that come to my mind at the moment, but I'm sure I'm overlooking quite a few. It's a doable project, but will be alot of work for all of the small details.
Click to expand...
See this is what i need i thank you soooo much!! I am swapping all the from suspension and hydroboost brake system over as well so that i have enough brake power and i am keeping the 4l60e in my 89 and t case and rear axle is beefier anyways it is the 14 bolt
 
Shitbox_garage said:
See this is what i need i thank you soooo much!! I am swapping all the from suspension and hydroboost brake system over as well so that i have enough brake power and i am keeping the 4l60e in my 89 and t case and rear axle is beefier anyways it is the 14 bolt
Click to expand...
Your 89 has a th700r4, not a 4l60e. ALL turbo 6.5's came with a 4l80e.
 
Shitbox_garage said:
See this is what i need i thank you soooo much!! I am swapping all the from suspension and hydroboost brake system over as well so that i have enough brake power and i am keeping the 4l60e in my 89 and t case and rear axle is beefier anyways it is the 14 bolt
Click to expand...
But is the 89's the 9.5" semi-floating 14 bolt (weaker) or the 10.5" full-floating 14 bolt (strongest) that can handle everything a 6.5 can dish out torque-wise? Just like the IFS differential, the lighter duty 8.5" or the 9.5" that still ran in front of the Duramax?
 
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