66 GMC Long to Short LS Swap
 

I've been lurking for a while, thought i should start a build thread before i start asking 100's of questions. This is my first build of any kind so I am figuring everything out as i go. This board has already been a world of help. I picked up a 66 GMC 910 LWB fleet side with a non running V8 with 4 on the floor It had been sitting in a farmers field for the last 20 years.

Plans for the build are a 5.5/7 static drop, disks up front and possibly rear, power steering, 6.0 LS/4L80E swap, rear mount gas tank and chopping it down to a SWB. Cab floors, rockers, supports and fire wall all need major rust repair.

This is how it sat for 20 years
[IMG]https://farm5.staticflickr.com/4730/...151f7658_z.jpg1 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4636/...98e6d038_z.jpg2 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4596/...54d91af5_z.jpg3 by Duncan Keith, on Flickr[/IMG]

Re: 66 GMC Long to Short LS Swap
 

Trailered the truck home and started to tear it down. Front sheet metal is in rough shape. Ended up cutting the front fenders to get them off, they were too far gone to bother saving. Grill support and rad support are pretty rusted out as well. Pulled the cab and built a quick roller stand for it. Pulled the old motor and trans as well.

[IMG]https://farm5.staticflickr.com/4689/...60684273_z.jpg4 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4733/...594623dc_z.jpg5 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4729/...6daaa62d_z.jpg6 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4590/...96de0b8d_z.jpg15 by Duncan Keith, on Flickr[/IMG]

Re: 66 GMC Long to Short LS Swap
 

Got to work on some rust repair on the cab. This thing is rough!! 20 years in that field was not kind to this truck. Cut out the old rocker, floor pan, cab corner and rear support. Fit the new rear portion of the floor pan and started welding it in.
[IMG]https://farm5.staticflickr.com/4738/...b42d08e9_z.jpg7 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4692/...2dca6264_z.jpg8 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4634/...848b3a30_z.jpg10 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4638/...49538dfc_z.jpg9 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4643/...a95bea7f_z.jpg11 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4588/...ccd53e87_z.jpg12 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4596/...d72ddddd_z.jpg13 by Duncan Keith, on Flickr[/IMG]

Re: 66 GMC Long to Short LS Swap
 

Switched gears for a bit and took advantage of an empty shop. Brought the donor truck in and got to work pulling the motor and transmission. Decided it would be easier to pull the cab before pulling the motor. I don't have an engine crane but there were plenty of excavators in the yard.
[IMG]https://farm5.staticflickr.com/4594/...8185a1d6_z.jpg16 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4635/...18e33c7e_z.jpg17 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4597/...3d8ff4dc_z.jpg18 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4730/...f1be82f7_z.jpg19 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4643/...ff3452a0_z.jpg20 by Duncan Keith, on Flickr[/IMG]

Re: 66 GMC Long to Short LS Swap
 

Welcome to the forum :D

Yes it looks like you have your work cut out for you with sheet metal repair, but it will be a nice truck when your done. Are you going to install the engine and trans as if, or go thru them?

Nice shop you have there too!

Re: 66 GMC Long to Short LS Swap
 

I will definitely be going through the motor. If budget allows it will be getting new heads, cam and intake.

Re: 66 GMC Long to Short LS Swap
 

Cool build, I’m doing the same thing except mines a step side. I’ll follow along. Good luck

Re: 66 GMC Long to Short LS Swap
 

Got a little time today to start back on the rust repair on the cab. This thing is like Swiss Cheese. Kinda overwhelming when i look at how many areas need repair.
Started working on the bottom of the rear pillar.
[IMG]https://farm5.staticflickr.com/4705/...b8607800_z.jpgIMG_3639 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4742/...57a0d0e7_z.jpgIMG_3640 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4765/...2c587cb7_z.jpgIMG_3644 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4716/...125c1ea2_z.jpgIMG_3645 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4769/...cc65c8ef_z.jpgIMG_3646 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4632/...ec52e13f_z.jpgIMG_3647 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4743/...349b4c2c_z.jpgIMG_3650 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4648/...0fef51a0_z.jpgIMG_3651 by Duncan Keith, on Flickr[/IMG]

Re: 66 GMC Long to Short LS Swap
 

Moved up to the front next. Have to repair the floor support before the floor pan goes in.
[IMG]https://farm5.staticflickr.com/4676/...d07795bc_z.jpgIMG_3636 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4678/...ebba0546_z.jpgIMG_3637 by Duncan Keith, on Flickr[/IMG]
Didn't want to order and wait for a replacement piece so I am trying to fab up a small section to patch in. Cut a piece of 16 gauge and made the first bend on the brake. Cant really get the tight radius I wanted so I lightly scored the second one with a cut off wheel and bent it over in the vice. I'll weld a bead on the underside to strengthen it up
[IMG]https://farm5.staticflickr.com/4758/...a1867c76_z.jpgIMG_3653 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4677/...cc3fe10d_z.jpgIMG_3654 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4632/...2f0a1f23_z.jpgIMG_3655 by Duncan Keith, on Flickr[/IMG]
I'll have to brace up the cab a bit tomorrow before i cut that support out.

Also found a great deal on a grill and rad support to replace my old rotted out ones
[IMG]https://farm5.staticflickr.com/4606/...e67fa890_z.jpgIMG_3638 by Duncan Keith, on Flickr[/IMG]

Re: 66 GMC Long to Short LS Swap
 

Wow, major effort Duncan! Glad to see you scored the rad support and grill. Following along..

Re: 66 GMC Long to Short LS Swap
 

Wow- lots of sheet metal work. I'll be watching to see how it comes out. Looks great so far

Re: 66 GMC Long to Short LS Swap
 

More sheet metal work the last few days. Finished patching in in the floor support[IMG]https://farm5.staticflickr.com/4649/...6d8c8019_z.jpgIMG_3657 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4765/...d942db8c_z.jpgIMG_3659 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4713/...b3675c9d_z.jpgIMG_3662 by Duncan Keith, on Flickr[/IMG]
Next up was the rear cab support. The first one I ordered was way too big, no way to make it work. Tried a different supplier off eBay. Not much better, about an inch too long and the angle where it meets the floor pan wasn't even close.
Are all these reproduction pieces garbage or is there somewhere better to order from?
[IMG]https://farm5.staticflickr.com/4666/...92064b95_z.jpgIMG_3669 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4708/...21a953d8_z.jpgIMG_3668 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4616/...43465afe_z.jpgIMG_3670 by Duncan Keith, on Flickr[/IMG]
Had to chop and weld this thing back together. Would almost be quicker to make one from scratch.
[IMG]https://farm5.staticflickr.com/4716/...52bf427f_z.jpgIMG_3671 by Duncan Keith, on Flickr[/IMG]
Eventually got it fitted and welded in. With that done i started on the front part of the floor pan
[IMG]https://farm5.staticflickr.com/4653/...d067b07b_z.jpgIMG_3664 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4666/...4709b657_z.jpgIMG_3663 by Duncan Keith, on Flickr[/IMG]

Re: 66 GMC Long to Short LS Swap
 

Kick panel and front cab support fitted and tacked in
[IMG]https://farm5.staticflickr.com/4765/...0a786349_z.jpgIMG_3673 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4650/...a5d0c26f_z.jpgIMG_3675 by Duncan Keith, on Flickr[/IMG]
[IMG]https://farm5.staticflickr.com/4660/...c9357e6d_z.jpgIMG_3679 by Duncan Keith, on Flickr[/IMG]

Re: 66 GMC Long to Short LS Swap
 

Most all the aftermarket patch panels are pretty much the same regardless of the sticker on them. However the Tri Plus/Key Parts, parts do seem to be the better of all of them.

Re: 66 GMC Long to Short LS Swap
 

Glad to see someone who's not afraid to cut.
My truck was a jig saw puzzle at times.
Nice work. Following along on this build.

Re: 66 GMC Long to Short LS Swap
 

Feels like all I am doing is cutting, not much original metal left
[IMG]https://farm5.staticflickr.com/4617/...ac4ec97a_z.jpgIMG_3665

Re: 66 GMC Long to Short LS Swap
 

Got back to work on the truck this weekend. Separated the trans from the motor and got the motor on the stand.Labelled and removed the wiring harness
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Decided to leave the rust repair alone for a bit and work on the frame. Started by removing all the old exhaust hangers. Cut off the brackets for the bump stops to make room for a notch.
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Next up it was time to make this thing a SWB. Removed the rear cab mounts and the first bed mount. Marked out the 12" section to be removed with a radius in the corners. Made the cuts with a cut off wheel and a plasma cutter. Fit up wasn't as good as I'd like on the passenger side. Man I wish I had more clamps for this job!!
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Welded it up and ground them smooth. I'll have to pick up some heavy flat bar and add some reinforcing plates on the inside.
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Clipped 8" off the back and relocated the rear cab mounts
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Re: 66 GMC Long to Short LS Swap
 

Continued work on the frame this weekend. Removed two bent up cross members in the front and rear along with the trans cross member.

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Had to fab up a new base for my engine stand, cheap bolt together one I bought wasn't cutting it. Got a smoking deal on an engine lift as well so I no longer have to use an excavator.

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Stripped the motor down to get it ready for clean up and paint. Got my Speed Engineering motor mounts in, just waiting for the new headers to arrive so I can set the motor in and build the new trans cross member

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Re: 66 GMC Long to Short LS Swap
 

Great start on a killer project. Nice shop and big boy toys also.

Re: 66 GMC Long to Short LS Swap
 

wow ...that's a lot of rust...glad to see your saving another old truck...you should save all those rusted pieces and then weldem all together when you get done and make a wall art outta that stuff...mini-x sure is like a bunch of extra hands...

Re: 66 GMC Long to Short LS Swap
 

Been working on a pipe notch, used a section of 5" heavy wall pipe and some 1/4" flat bar. Plumbed a centre line up from the axle, marked out the pipe notch and cut it out with the plasma cutter. Made a cardboard template of the frame and cut a piece of flat bar to match it. Fit everything up and welded the pipe to the plate. Then I used clamps, a torch and hammer to shape the flat bar to the curve of the frame.

https://farm5.staticflickr.com/4760/...f16f7b80_z.jpghttps://farm5.staticflickr.com/4750/...9ff7c41c_z.jpghttps://farm5.staticflickr.com/4760/...ac972756_z.jpg

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Still have to weld it in and box in the inside. Ill probably round off all the corners and drill a few holes to plug weld in the middle of the plate.

Re: 66 GMC Long to Short LS Swap
 

Love the work so far,your pile of rusty cut out body parts looked just like mine did,hard to believe how fast it piles up!

Re: 66 GMC Long to Short LS Swap
 

Very nice work!

Re: 66 GMC Long to Short LS Swap
 

great work! also working on a 6.0/4l60 excited to see your cleanup.

Re: 66 GMC Long to Short LS Swap
 

Hopefully I'll get to see this in person sometime.

Re: 66 GMC Long to Short LS Swap
 

I've been plugging away on the frame lately. Really pushing to get all the new cross members done and everything welded up so I can get this thing blasted and lay down some paint. I am really tired of rust, just can't wait to have at least one piece of this truck cleaned up and looking like new! Its been a bit like Christmas for me with boxes of shiny parts showing up at my door. Headers came in as well as my Grand Slam kit from CPP. Got my power steering kit from POL as well.

Finished up the notches for both sides and got them welded in. I'll probably box in the insides for good measure.

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Ground the welds flat on the inside of the frame rails where I shortened the frame. Made up some fish plates and welded them in.

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Fabbed up a new cross member to replace the twisted and bent one up front. Decided to get a little Tig practice in. Slowly getting better at it.

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Mounted up the new PS box and plates and welded them in along with the finished cross member up front.

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Just one cross member left to build and that is for the transmission. Got to work setting the motor and trans in. Had to move the stock V8 perches up to the front mounting holes. Bolted up the Speed Engineering LS swap motor mounts and put the old rubber mounts in the rear hole locations to set the motor as far forward as possible and dropped the motor in. As it sits right now the oil pan is sitting on the the front clip and the rubber mounts aren't quite fully seated on the perches so it looks like I will have to shim the perches up a little. I took a quick measurement and the motor is going to be really close to the fire wall, I'll have to throw the cab on to see just how close.
Headers are from Speed Engineering as well. They bolted in and fit like a glove inside the frame rails. I'll have to trim one little piece on the bell housing on the passenger side to make them work.

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I am hoping to get the position of the motor finalized tomorrow and start building the trans cross member. Gotta do some homework on setting the driveline angle. Plan is to use a magnetic angle gauge on the end output shaft of the trans. From the reading I've done I need to match the angle of the output on the diff. Should I zero the gauge out on the frame rail before measuring the angle of the diff?

Re: 66 GMC Long to Short LS Swap
 

very nice,and nice welds,i tried tig 30 yrs ago stuck with stick and mig LOL,nice job on crossmember!

Re: 66 GMC Long to Short LS Swap
 

I set the frame at 0 degrees, put the motor and trans around 3 degrees down using the trans crossmember, and then set the rear end to 3 degrees up.

Its not very hard once you are there doing it.

Re: 66 GMC Long to Short LS Swap
 

Nice work, following.

Re: 66 GMC Long to Short LS Swap
 

Well I got the motor and trans in their final position. Had the motor in and out several times to change the position of the mounts and the perches to get everything to clear. Haven't had a chance to put the cab back on to check firewall clearance. Judging by the measurements I took its gonna be close.

Got to work building the trans mount. I quiet often draw everything out on my welding table and use that to lay out the parts.

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Tig welded the parts up

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Centred and squared it up, then drilled it for a couple 1/2" bolts

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Right now the transmission is set at 5 degrees but will be easy to shim if needed. I jacked the frame up level and checked the angle of the differential. It is sitting at 10 degrees up. I'm hoping that will decrease a bit when I put the lowering springs in. Then I guess I'll have to shim it the rest of the way to match the transmission.

I'll be getting to work stripping the suspension off and get everything sandblasted. Getting closer to paint and shiny new parts!!!

Re: 66 GMC Long to Short LS Swap
 

Id make the center of the lower section of your trans crossmember thicker. Strength is gained by the height of steel not the thickness.

Re: 66 GMC Long to Short LS Swap
 

I would bet that crossmember could handle the weight of the entire truck with little to no deflection.

Re: 66 GMC Long to Short LS Swap
 

I thought about beefing up the bottom a bit more but decided the 3/8 flat bar was enough. After getting it welded up it is pretty stout, the frame rail its mounted to will bend before it does.

Got my Boyd's tank from UPS today. Man is this thing pretty!! Welds are a thing of beauty, it will be a real shame to hide this thing under the bed. I really like that it came complete with in tank pump and sending unit.

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Started working on getting the front suspension off. Couple hours with a torch, big hammer, pickle fork and a lot of swearing got the job done.

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Found both springs were broken when I pulled them out.

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Re: 66 GMC Long to Short LS Swap
 

Finished removing the rest of the suspension. Old ball joints are out, trailing arms off. Ready to get everything sandblasted.

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Hoping to get everything painted, reassembled and back as a full roller in the next few weeks.

Re: 66 GMC Long to Short LS Swap
 

Nice build thread.
Currently working in the Calgary area so maybe will get to see the build when completed!

Re: 66 GMC Long to Short LS Swap
 

First round of blasting got done this afternoon. Took the suspension parts down to try out a DIY sandblasting place. Best money I have spent in a while!! Endless high pressure air supply, no waiting, no clean up. Feels so good to have a few parts without rust and 50 years of grime on them. Hoping to head back there with the frame and the rear end in the morning. Supposed to snow for the next 4 days starting mid morning so I have to get this done quick.

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Re: 66 GMC Long to Short LS Swap
 

That’s awesome man, a DIY blasting place is a great idea. Never heard of that before. Build is looking good

Re: 66 GMC Long to Short LS Swap
 

Ha, I've never heard of a DIY blast place. What sort of blast media is used?

Excellent job blasting. That's how the blasted parts should look, 100% white metal. Be careful doing any sheetmetal.

Re: 66 GMC Long to Short LS Swap
 

Yeah this place is great. The media is a medium grit sand. Took care of the rust and grime really quick but didn't seem to dig into the metal. It sits on 5 acres and has 6-7 stations big enough to bring a large trailer.

I loaded up the frame and rear end and tried to beat the snow storm this morning. Got half way to the blasting place and the storm hit. Looks like I will be waiting another week before I can get the frame blasted. Will probably tear down the LS and see what kind of shape its in. Plan is to send it off to be hot tanked and honed. Hoping I can reuse the pistons and just re-ring them. I'll be replacing all the seals and gaskets.

Not sure what I want to do for a cam. I want something that will work with the stock motor for now and L92 heads in the future.

Re: 66 GMC Long to Short LS Swap
 

Do they charge by the hour? How much is it?