66 GMC Long to Short LS Swap

[Duncan K]

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]1 by Duncan Keith, on Flickr[/IMG]
[IMG]2 by Duncan Keith, on Flickr[/IMG]
[IMG]3 by Duncan Keith, on Flickr[/IMG]

[Duncan K]

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]4 by Duncan Keith, on Flickr[/IMG]
[IMG]5 by Duncan Keith, on Flickr[/IMG]
[IMG]6 by Duncan Keith, on Flickr[/IMG]
[IMG]15 by Duncan Keith, on Flickr[/IMG]

[Duncan K]

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]7 by Duncan Keith, on Flickr[/IMG]
[IMG]8 by Duncan Keith, on Flickr[/IMG]
[IMG]10 by Duncan Keith, on Flickr[/IMG]
[IMG]9 by Duncan Keith, on Flickr[/IMG]
[IMG]11 by Duncan Keith, on Flickr[/IMG]
[IMG]12 by Duncan Keith, on Flickr[/IMG]
[IMG]13 by Duncan Keith, on Flickr[/IMG]

[Duncan K]

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]16 by Duncan Keith, on Flickr[/IMG]
[IMG]17 by Duncan Keith, on Flickr[/IMG]
[IMG]18 by Duncan Keith, on Flickr[/IMG]
[IMG]19 by Duncan Keith, on Flickr[/IMG]
[IMG]20 by Duncan Keith, on Flickr[/IMG]

[Captainfab]

Welcome to the forum

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!

[Duncan K]

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

[Chad215]

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

[Duncan K]

More sheet metal work the last few days. Finished patching in in the floor support[IMG]IMG_3657 by Duncan Keith, on Flickr[/IMG]
[IMG]IMG_3659 by Duncan Keith, on Flickr[/IMG]
[IMG]IMG_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]IMG_3669 by Duncan Keith, on Flickr[/IMG]
[IMG]IMG_3668 by Duncan Keith, on Flickr[/IMG]
[IMG]IMG_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]IMG_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]IMG_3664 by Duncan Keith, on Flickr[/IMG]
[IMG]IMG_3663 by Duncan Keith, on Flickr[/IMG]

[Duncan K]

Kick panel and front cab support fitted and tacked in
[IMG]IMG_3673 by Duncan Keith, on Flickr[/IMG]
[IMG]IMG_3675 by Duncan Keith, on Flickr[/IMG]
[IMG]IMG_3679 by Duncan Keith, on Flickr[/IMG]

[Captainfab]

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.

[LostMy65]

Originally Posted by Captainfab

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.

I appreciate you posting that. I don't have a horse in the race, but I still like to steer people in the right direction. There are some that argue they all come from the same place but with different stickers. I would concede and say that may be so, but the TriPlus / KeyParts are an obvious better quality. There's a thread in these forums where pictures are posted showing the obvious differences.

[Bomp]

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.

[Duncan K]

Originally Posted by Bomp

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.

Feels like all I am doing is cutting, not much original metal left
[IMG]IMG_3665

[Duncan K]

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
[IMG]
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.

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!!

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.
[
Clipped 8" off the back and relocated the rear cab mounts
]

[Duncan K]

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




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.



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

[CHIZZLER]

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

[mongocanfly]

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...

[Duncan K]

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.









[IMG]

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.

[Rusty63]

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!

[Bennett68C10]

Very nice work!

[Jferrante]

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

[Notch1988]

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

[Duncan K]

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.



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.



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.



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



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.





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?

[tinydb84]

Originally Posted by Duncan K

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?

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.

[1enick72]

Nice work, following.