90 GMC C3500 dually 6.0 4L80E swap in Frankentruck!

[JunkYardPirate]

I've got this thread going in another site, going to condense it here.
This is how my truck was when I started Just finished almost the entire truck.

and a bunch of dudes that had a chop shop seemed to take a liking to it also. Oct. 2nd around midnight they took it. fortunately my club has friends in Legal places and within 2 hours of me posting the news on facebook a detective saw it roll into the chopshop he had been watching for 6 months.
long story short he had to wait till all the guys put a hand on it so he could bust them all and they had stripped it down pretty good by then.


got it back the next day and decided its time to use a crappy situation as motivation to do some upgrades.

I had an 05 express 3500 with 74,000 miles a 6.0 and 4L80 so I got to chopping!

pulled the engine, trans, entire harness inside cab and under hood and lights!
I'm also using the fuel tank from the van being its the 15 passenger it had the bigger tank, fuel lines, cluster and column.
I've also picked up a 95 dash, 95 doors.
To start with I already had 99 seats, overhead console rear seat and center console in the truck, 5-7 drop, Alcoa wheels, custom paint, rear helper bags with tank and compressor, etc... etc... way too much to list.

The Plan is to use the 95 dash, 95 door guts and panels, 05 cluster, the entire 05 harness including lights. 05 column (surprisingly fits the 95 mount)

I know I need to change the column / brake pedal mount, already started that too. and of course the 05 6.0 and 4L80.

so Far I have stripped the van for all its goods, pulled the old dash and harness test fit the 95 dash (fits great)

and today pulled the dash and all wiring back out and started taking out my 454 TBI and 700R4 got everything ready to come out, hopefully will get it out in the morning.



12-16-13

got back into it tonight, didn't have allot of time but I did get the 454 and 700R4 pulled out. got most of the wiring out of the truck and started prepping the 6 liter and 4L80 to go in.
still need to get the rest of the wiring out after I finish gutting I should only have the taillight and trailer wires left, everything else including dash wiring, door wiring etc is coming from the donor.
looks like the fuel tank and lines from donor are going to work too!
so I will pretty much be reinstalling all of the 05 wiring into the 90 cab / chassis. just have to splice in the tail lights. and 95 door panels.
heres a few pics from tonight. didn't take many when we tore the van apart to get all the donor parts.

Out with the old.....



need to get in here and clean and paint..


heres the new 6.0 and 4L80 standing by!



have not done a full swap with all wiring and electronics included before..
im using the column and cluster from the 05 also!! didn't have to cut anything!!

cluster works great!! and yes that's the actual mileage from the donor, Owned it since new till one of my employees got T-Boned!





12-20-13

anyway, a little more progress tonight.
stabbed the engine and trans in to figure out how I want to do the motor mounts, im extremely confused as to why people are cutting up their trans cross member or using adaptors? I was able to unbolt mine and slid it into place. once I get the motor mounts done it looks like it will bolt into existing holes in the frame that were behind the stock mounting location.


going to blast it and paint it while its out. now that I have an idea of where the engine will sit and see everything clears I can pull it back out and clean and paint the engine compartment.


done for tonight, will get back on it tomorrow. Hope to get allot done this weekend.

12-21-13

Beyond excited with todays progress, got the engine and trans in!
I ended up sliding back the existing trans crossmember and mounted the trans to that. then we played around with the motor mounts and ended up cutting the frame mounts from the van and retrofitted them to the truck. total cost =$0
so now my truck is using the stock 05 express van 3500 motor mounts.
lots of room. under the hood compared to the 454. amazingly the driveshaft is perfect, just need to swap the yoke to the one from the van.

only got in a few hours today. tomorrow I can clean the hell out of everything and work on getting the van fuel tank and lines in and then start routing the wiring and hope to have time for the column swap. Maybe start putting it back together.
here's a couple of shots I took from my phone.
Looks goooood in there!



12-24-13

here's a shot of the way I did the motor mount.
we took the engine mount perches from the van. they bolt to the frame in the van, after cutting the stock frame mounts off the frame of the truck we could then cut the van mounts down to contour the frame of the truck.
we bolted them to the engine, when the engine was in the correct spot I tack welded them to the frame. unbolted the engine and finished the welding and shot some black paint. saved quite a bit of money not having to buy adapters.


Taking a break for Christmas will get back on it later in the week!
hope to a have a video of it running soon!

Merry Christmas everyone!

-Jim

[canada4g63]

Damn that suck someone broke into your truck, glad to see your putting it back together in a good way.

[JunkYardPirate]

Yea they tore it up pretty bad. In total it was just over $15grand in damages.
I hardley got to work on it today. Wrestled with some of the wiring the driveshaft and fuel tank got frustrated because the truck is soo low even on jack stands and I'm burned out from Christmas. I decided to tow it over to the shop where I have a lift. Should make the rest of the work fly by having everything we could need at my disposal.
So tomorrow morning I'm going to flatbed it over there and hopefully should have a running truck in a day or two.
Will update this as soon as I have some progress.

[JunkYardPirate]

Damn that suck someone broke into your truck, glad to see your putting it back together in a good way.

Wish it was just broken into. They stole the whole truck! There's allot I didn't get back so unfortunately I'm going to have to repaint. Was a new paint job too!!

[JunkYardPirate]

didn't get it to the shop yet, going to get on that in the morning, I did get a few hours in tonight. I took out the old 90' brake pedal assembly seen here.


then was able to get the 95 assembly in and welded into place.
we drilled the welds out and welded the new setup in.
this is it before welding it in.



after that I was able to get the 05 column into place. fit perfect!



tomorrow is the big day, will get it up on the lift and get the tank swapped and start hooking everything up!

[JunkYardPirate]

Got some time to work on the truck today. I got the yoke on the driveline, and it was the perfect length, no modification (besides yoke) needed.


so we went ahead and got her up on the lift and mounted into place.



then good ol' Murphy jumped up and bit me!
everything was going great! I knew it was tooooo easy up till this point.
time for the fuel tank, got the old one out.....


went ahead and started to test fit the Van tank into place, looked real good at first then noticed a section of the frame just wouldn't let it go in. so down it came, not going to work.



so now I'm trying to retrofit the pump from the van into the truck tank. not sure if im going to go that route yet. took the pumps and sending units out of both and will play around with some other configurations.. here is the van pump disassembled.


am going to look into maybe a late model gm dually tank or a shorter van wheelbase tank..my main goal is to retain the fuel gauge with the 05 cluster so I need that sending unit in the tank. need a day to think over how I am going to tackle it, Suggestions would be awesome!! shop closed early tonight for new years so I started playing around with my new grill ornament design pretty sure im going to use this..



this is my 3D prototype machine, pretty fun, can print damn near anything in ABS plastic. going to come in handy for a few more custom parts im going to make for the interior and making brackets to retrofit all the 05 stuff.

anyway, Happy New year everyone, will be back on it on Thursday going to take tomorrow off.

[kewljay223]

why exactly are you trying to swap tanks/ sending units??? the pumps themselves are direct swaps utilizing the stock units.... i have a 95 and all i did was change the pump to a delco 381. straight forward.. unless your in cali and doing a legal swap like i did then there is more involved which i can try and help with but idk your loacation... just saying there is no need to swap the full unit out.... just the pump itself will be fine to get the pressure you need...

[kewljay223]

k..my main goal is to retain the fuel gauge with the 05 cluster so I need that sending unit in the tank. need a day to think over how I am going to tackle it

i guess i missed that... i think your gonna have to do what i did as you have two options. option one.... install newer style sending or tank with new sending unit like your trying to do along with a new gauge cluster for everything to work properly. the older gauges use a different resistance than the newer ones. plus the pcm supplies 5v to the sending unit rather than 12v.... option 2..... do like i did, keep the same tank, change fuel pump to the newer style, and add the sending unit to the tank.. not the whole thing... just the float part. i basically have two floats in my tank now. the original that uses 12v to keep the old gauge working like it should. and the new added one just so the pcm can see whhat the fuel level is at. if you do this though, you will need to add wires going into the tank...

[JunkYardPirate]

my truck is a 90 so the newer 95+ fuel pump assembly wont fit in it. I am thinking maybe a 99 truck tank might work. was worth a shot to get the 05 tank in there but that would have been too easy.
I might just go with an inline fuel pump and just put the new sending unit into the tank so I can keep the 05 cluster fuel gauge working.
im not keeping any of the 90 interior components at all. the column is 05, the dash is 95 the dash harness is 05 the AC blower is the only thing inside still 90.
this is why its a Frankentruck! I am putting parts from many others into a 90 cab..

[JunkYardPirate]

why exactly are you trying to swap tanks/ sending units??? the pumps themselves are direct swaps utilizing the stock units.... i have a 95 and all i did was change the pump to a delco 381. straight forward.. unless your in cali and doing a legal swap like i did then there is more involved which i can try and help with but idk your loacation... just saying there is no need to swap the full unit out.... just the pump itself will be fine to get the pressure you need...

Were you able to put the delco 381 in the old pump hanger?
That sounds like my best option right now without going external.
If I can put the. 381 in place of the 90 pump I would just ad the sending unit to the old hanger?
Does that make sense?
I'm in Las Vegas by the way but for emissions I only need the tailpipe probe and a good gas cap. No obdii on a 90 so they won't have to check the computer when I smog it. Which is coming up soon. Forgot about that.