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Posted By: DCol63 LS swap - October 16th 2018 8:07 am
Hi everyone,

I have a 1974 GMC 1500 and I'm looking to put a Gen IV, 6.0 L with a 4L80. Has anyone come across any particular problems with the install such as clearance to the frame or the doghouse? One concern I have is that the a/c compressor may be a problem. Any advice or suggestions would be greatly appreciated.
Thank you in advance.
Posted By: Wedgy Re: LS swap - October 16th 2018 3:07 pm
DCol83, Hello and welcome to the Site!

Pretty ambitious swap, and gotta love Goin Big!

Safe to say the front cross member comes out. Seen a few swap threads on here with pics. LS? IDK. DynoDave just posted up some info on the Chevy/GMC post 1995 GMT Vans. The newest models do have the 6.0 motor. Size never mattered in the Smallblock swaps I've done, but measuring a factory Big Block G30 will tell you what they crammed in under that Doghouse.

Why couldn't an AC compressor be remotely located, and driven by an electric motor?
Posted By: frscke1 Re: LS swap - October 16th 2018 3:20 pm
Welcome to the site DCol ....
Posted By: DCol63 Re: LS swap - October 16th 2018 7:00 pm
Thank you,
Is a 5.3 going to be much different?I thought they were the same size. I figure that I may have to maybe notch the cross member and maybe change to a lower profile oil pan.i know there are motor mount kits out there and may have to modify those. I definitely want a/c as I plan to make it a daily driver.
Posted By: CatFish Re: LS swap - October 16th 2018 8:29 pm
These guys may be helpful:

http://www.brphotrods.com/products/88-98%20Truck/index.html
Posted By: DCol63 Re: LS swap - October 16th 2018 10:07 pm
Looks like a good start. I'll give them a call tomorrow.
Thank you
Posted By: Wedgy Re: LS swap - October 17th 2018 2:02 am
Originally Posted by DCol63
Thank you,
Is a 5.3 going to be much different?I thought they were the same size. I figure that I may have to maybe notch the cross member and maybe change to a lower profile oil pan.i know there are motor mount kits out there and may have to modify those. I definitely want a/c as I plan to make it a daily driver.


https://www.onallcylinders.com/2017...ory-overview-gen-iiiiv-ls-engine-family/

Here's some more LS info to go along with the cool stuff from Catfish.

Good point about the smallblock size comparison. I was wondering more about the height and location of the induction plenum, throttle body, exhaust and driven accessories. You might be able to see how the newer vans mount those on the LS block to fit under the Express cowling and doghouse and may be able to use that method in your build.

My smallbocks were in a '70 C10, and a '65 Impala. You'll be going way deeper that that. Go Team LS swap!
Posted By: tuner4life Re: LS swap - October 17th 2018 12:20 pm
I wonder if you sourced your engine setup from a newer Express van if the belt drive would be re-arranged to better fit with the A/C? I've never seen one in person to compare so I'm just speculating.
Posted By: Wedgy Re: LS swap - October 18th 2018 12:03 am
https://www.youtube.com/watch?v=arAnA65RMNo

Some more info for your LS swap D,

No more Gasoline powered Vehicles by 2050? I find I kinda don't think so.

Here's an LSIII going into an early Nova Wagon. Worth watching. Nice shorty headers that look promising. Then, at 6:20, She goes into detail concerning the motor plate/engine motor mount components. Mentions difficulties with the AC drive, and names some suppliers in the video. Funny flexplate lessons. Flip Flops made me cringe, but one loaded ratchet to a toe will cure that.

Hope this helps. Good American Family Fun Video. Cute Dog, Good Skills, Nice Car!

Quality Chevrolet never could get the correct lower mount for one side. I ended up chaining down the high side of the motor in the Impala. '73, '74? Always a good idea anyway. Especially a 283 backed up by a PG... grin Traded that $250 '65 Impala to my BILaw for a '59.
The drivetrain then went into his Econorail. shift
Carlsbad Raceway is buried under a Business Park now. But the Heartbeat of America lives on.
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