Been on the board a while now, have already learned a lot from the collective wisdom here. I was previously (and am still) a chevy truck guy and have been active on 67-72chevytrucks under this same handle. Been working on this build for a few months, finally have time to document the build. Gonna be a few posts while I'm on a long train ride today, bear with me here.
Bought this 1989 GW in late January. Had almost 200K miles and needed a fuel pump. Had the original 360/727/229 combo, with a Howell EFI system. The plan was to drive it for a while and then LS swap it. After driving it for a _little_ while, I realized the swap was going to make things a lot more enjoyable. It had a stalling issue and just general sluggishness, which I know is par for the course with these engines.
It is an East Coast car and shows it in places. It’s eventually going to need some exterior panel work and a paint job but as I always do with my projects, I’m focusing on the mechanicals first. Goal is to get it back on the road this year with the new powerplant and then paint next year.
89 GW build - 5.3 swap
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midlifer
Topic author - Posts: 23
- Joined: Wed Feb 01, 2023 6:10 pm
89 GW build - 5.3 swap
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midlifer
Topic author - Posts: 23
- Joined: Wed Feb 01, 2023 6:10 pm
Re: 89 GW build - 5.3 swap
Post 2:
So I set out to source an engine/trans, and found a DBC 5.3/4L60e/246 combo out of a 2003 Avalanche with 103K miles. Got to hear it run before it was pulled and it sounded good. Later, when I got the valve covers off, it was apparent that the PO didn’t keep up with oil changes, either that he was Australian and added vegemite to the mix. When we pulled the pan and cleaned everything out, the cylinders/valves/bearings looked good.
Trans was another story. Knowing the reputation of the 4L60e I went ahead and took it to a rebuilder, and it had a few issues. He went through it and addressed everything and strengthened it up so it’ll be good to go.
So I set out to source an engine/trans, and found a DBC 5.3/4L60e/246 combo out of a 2003 Avalanche with 103K miles. Got to hear it run before it was pulled and it sounded good. Later, when I got the valve covers off, it was apparent that the PO didn’t keep up with oil changes, either that he was Australian and added vegemite to the mix. When we pulled the pan and cleaned everything out, the cylinders/valves/bearings looked good.
Trans was another story. Knowing the reputation of the 4L60e I went ahead and took it to a rebuilder, and it had a few issues. He went through it and addressed everything and strengthened it up so it’ll be good to go.
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midlifer
Topic author - Posts: 23
- Joined: Wed Feb 01, 2023 6:10 pm
Re: 89 GW build - 5.3 swap
Post 3: pics of the dirty engine and after we cleaned it up. The borescope did not show any cylinder damage and the bearings look good so fingers crossed. There was a fair bit of sludge in the pan but no shiny sparkles.
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midlifer
Topic author - Posts: 23
- Joined: Wed Feb 01, 2023 6:10 pm
Re: 89 GW build - 5.3 swap
Post 4:
Next was getting the front clip off and pulling the engine. No real surprises in the front sheet metal – a few minor cracks in the grill and missing tabs, etc, but it all should go back together fine. My buddy Paul (a fellow LS swapper from the C10 world) came and helped me get the engine out. That’s when the fun began. Once we got a good look at the frame it appeared that it had rot that wasn’t going to be easy to fix. When I dropped the gas tank I also found previous repairs to that section. Paul found a local frame on eBay and it turned out the seller was the guy who was buying the engine and Howell system from me, so we did a swap. The project just got longer and more involved but when I’m done I know it’ll be right.
Got the frame home and it really wasn’t in bad shape. It came with a harness, brake lines and old leaf spring shackles still attached. Those shackles were fun getting off, especially the rear ones in the “box”. The bolts were all rust-seized to the bushings.
The body mounts needed addressing, which was a great excuse to upgrade my MIG welder to a 220V unit. I fixed those up then set about POR 15’ing the frame. My friend old George came by and helped me move the axles over and install the new leaf springs.
He also helped me lift the body off the frame. We used my lift and a chainfall. The body mount bolts were interesting to say the least, a number of them had rusted considerably and just snapped when I applied impact to them. Glad I ended up doing a frame-off on this thing. The frame has been resting on the lift arms (which are pinned with the safety bar) and cinderblocks for the past 2 months while we work on the frame.
Next was getting the front clip off and pulling the engine. No real surprises in the front sheet metal – a few minor cracks in the grill and missing tabs, etc, but it all should go back together fine. My buddy Paul (a fellow LS swapper from the C10 world) came and helped me get the engine out. That’s when the fun began. Once we got a good look at the frame it appeared that it had rot that wasn’t going to be easy to fix. When I dropped the gas tank I also found previous repairs to that section. Paul found a local frame on eBay and it turned out the seller was the guy who was buying the engine and Howell system from me, so we did a swap. The project just got longer and more involved but when I’m done I know it’ll be right.
Got the frame home and it really wasn’t in bad shape. It came with a harness, brake lines and old leaf spring shackles still attached. Those shackles were fun getting off, especially the rear ones in the “box”. The bolts were all rust-seized to the bushings.
The body mounts needed addressing, which was a great excuse to upgrade my MIG welder to a 220V unit. I fixed those up then set about POR 15’ing the frame. My friend old George came by and helped me move the axles over and install the new leaf springs.
He also helped me lift the body off the frame. We used my lift and a chainfall. The body mount bolts were interesting to say the least, a number of them had rusted considerably and just snapped when I applied impact to them. Glad I ended up doing a frame-off on this thing. The frame has been resting on the lift arms (which are pinned with the safety bar) and cinderblocks for the past 2 months while we work on the frame.
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midlifer
Topic author - Posts: 23
- Joined: Wed Feb 01, 2023 6:10 pm
Re: 89 GW build - 5.3 swap
Post 5: more photos for the last post
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midlifer
Topic author - Posts: 23
- Joined: Wed Feb 01, 2023 6:10 pm
Re: 89 GW build - 5.3 swap
Post 6:
I got the Novak mounts for the 5.3, and I also sourced a NP241 transfer case. I did pretty extensive research into wiring up the 246 and even sourced a control module and switch, and I’m not afraid of electrical stuff but in the end it seemed that the 241 would be a better plan. Got a t-case shifter out of a 2000s Silverado and the linkage to go with it, hopefully that will go in fairly easily. Gonna try using the Lokar shift rod or cable for the column shift, if anyone has opinions as to which works better, I’m all ears.
Laying the engine in place with the Novak mounts was fairly painless. I moved the transmission crossmember to the rear holes and it seems to line up nicely with the rear mount on the trans. When I get the body back on and the new driveshafts back from the shop, I’ll fab up a mount using the collective wisdom I’ve gleaned from this forum. Went through the diffs, popped covers and inspected, all seems in order as do the back brakes. I will eventually get the wheels polished and put new tires on, again, after getting the engine started and the truck put back together.
What I’m currently working on is the underside. I spent this past Saturday scraping gunk and wire wheeling rust – Mike Rowe would have been proud. I had to stop 4 times to sweep the floor and clean off my face shield, and my N95 mask was brown by the time I was done. Next step will be to wash off the remaining grease then prep the metal, POR15 the rusty bits, self-etch primer on the rest and then shoot POR15 bedliner on the underside. I also have some rot repair to do on the sheet metal that the rocker panels attach to. I’ve already cut and bent the metal for that, but gonna wait until I get the body on the frame to address that. Rust you are a worthy foe!
I got the Novak mounts for the 5.3, and I also sourced a NP241 transfer case. I did pretty extensive research into wiring up the 246 and even sourced a control module and switch, and I’m not afraid of electrical stuff but in the end it seemed that the 241 would be a better plan. Got a t-case shifter out of a 2000s Silverado and the linkage to go with it, hopefully that will go in fairly easily. Gonna try using the Lokar shift rod or cable for the column shift, if anyone has opinions as to which works better, I’m all ears.
Laying the engine in place with the Novak mounts was fairly painless. I moved the transmission crossmember to the rear holes and it seems to line up nicely with the rear mount on the trans. When I get the body back on and the new driveshafts back from the shop, I’ll fab up a mount using the collective wisdom I’ve gleaned from this forum. Went through the diffs, popped covers and inspected, all seems in order as do the back brakes. I will eventually get the wheels polished and put new tires on, again, after getting the engine started and the truck put back together.
What I’m currently working on is the underside. I spent this past Saturday scraping gunk and wire wheeling rust – Mike Rowe would have been proud. I had to stop 4 times to sweep the floor and clean off my face shield, and my N95 mask was brown by the time I was done. Next step will be to wash off the remaining grease then prep the metal, POR15 the rusty bits, self-etch primer on the rest and then shoot POR15 bedliner on the underside. I also have some rot repair to do on the sheet metal that the rocker panels attach to. I’ve already cut and bent the metal for that, but gonna wait until I get the body on the frame to address that. Rust you are a worthy foe!
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farmboy73045
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- Joined: Mon Oct 02, 2023 6:38 am
Re: 89 GW build - 5.3 swap
I am real curious as to how you hooked up transfer case . The one I am building for a friend has come up with a stalemate as per linkage. He wants to use the original tc. Was just curious as if that was what you did or did you opt for a newer style tc .