LS3 swap thread

[347strokin]

Reading this gives me all the good feels. I am literally doing an almost identical swap as you. I'm gathering the last few parts needed right now before I start tearing into mine. It's my daily driver so I am trying to keep my down time to a minimum. I have a 2wd LWB 1978 GMC C15 that I am swapping a GM crate LS3 and 4l80e into. Mine happens to be brown as well. I will start a build thread soon on mine and will do my best to keep it up to date.

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Sick, love it! I can't wait to get her running. But...I just picked up a 78' Blazer 2wd! Luckily it's not at home yet so I can still concentrate on Old Brown.

 

[347strokin]

In my dreams! but 5.3 swap and req., all else stays, mine was brown, needed a bit of hood and top protection, got carried away with the rattle can 18 years ago lol.
Heck, I would like just a CA legal sb to putt around right now. The smog rules here let you do an E rod swap, not much else.

Yikes, those smog rules suck for us hot rodders.

 

[Mr.Rogers]

How's the swap going for you so far? How hard was it to get that Blazer tank in? Where are you going to place your fuel filler?

 

[Nasty-LSX]

347strokin, can I call you to pick your brain on a few things?

 

[347strokin]

How's the swap going for you so far? How hard was it to get that Blazer tank in? Where are you going to place your fuel filler?

Hey buddy. It was actually a lot easier than I initially though. I just moved the spare tire cross member further back on the frame. This now sits on top of the front of the gas tank helping keep it level with a slight incline to the rear.

Then I mounted a piece of angle iron to the frame in front of the fuel tank to hold it on place so it won't slide around. This is also where I drilled and mounted the front saddle straps. The rear saddle straps can be drilled and mounted on the rear frame cross member.

I plan on cutting a small hole in the rear of the bed and putting a locking gas cap there.

I mounted the fuel filter/regulator on the frame in the factory filter frame holes.

Hindsight is 20/20 but I should've mounted the fuel tank with the pump on the drivers side as this is the side where the LS motor fuel injection line is. So I had to run the fuel line from the passenger to the driver side.

Let me know if you have any questions and I'll try and find the write up I used to do it if you like.

 

[347strokin]

347strokin, can I call you to pick your brain on a few things?

Of course. Any time. Send me a DM and I'll let you know when I'm free.

 

[347strokin]

Alright, back at it! Got some more work done this set off work. Had to pull the motor again to install the new oil pan, oil pick up tube, dipstick etc. This is the Hummer H3 pan, also known as the Muscle Car Pan. It clears the front crossmember nicely. It does hang a touch below the cross member but it should be alright. I'll try to get a pic of the under hang when I get home again. I just couldn't justify paying the premium to go to the F Body or CTS V pan.

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[347strokin]

A few more pics of the engine pull. And a little Scotch.

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[347strokin]

I replaced the stock two wire coolant temp sensor with a three wire sensor. This allows me to use the third wire to connect to my temp gauge in the truck.

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[347strokin]

The two things my PSI Conversion harness didn't have wired was for the cooling fans and for the fuel pump. I wired up a two relay/two fuse system for the cooling fans. The PSI Harness does supply trigger wires for each relay to turn on at a set temp. All connections are twisted, soldered and heat shrunk. They will also all be loomed up so it looks nice.

PSI does supply a relay on the fuse block for the fuel pump so that was a little quicker to build.

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[347strokin]

Got the Hooker Blackheart headers all bolted up. On a a side note, the dipstick works perfect with the headers.

I also bought and gapped new spark plugs and picked up some Accel Extreme 9000 ceramic plug wires.

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[347strokin]

I will be adding some red accents throughout the engine compartment. I started with this oil catch can I picked up cheap on Ebay. It has a dipstick, baffle, rubber o rings on all the fittings etc. And was cheap! I fabbed up my own mount bracket out of steel flat bar and primed/painted it up.

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[347strokin]

You can see by the above few pics that I have got the entire PSI Conversion engine/trans harness all wired up. Everything fits perfect and it was easy peezy. I'd definitely recommend them. I also purchased a fuel pump kit from them. I've called their customer service probably 6 times so far and they've always replied with quick, friendly answers.

 

[347strokin]

Measuring up for new power steering lines. I have a local shop fabbing some up.

If you have a sharp eye, you can see where I broke off the plastic nipple on the bottom of the power steering reservoir. Oops. So I drilled and tapped a brass fitting in there. I used fuel/oil resistant Teflon tape and JB welded it.

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[347strokin]

Well I'm back at work now.

Still to do when I'm home again:

-Install power steering lines.

-Fab up and route trans cooler lines.

-Buy new rad hoses.

-Fill engine and trans with oil. Fill coolant system.

-Cut out hole in box for fuel filler.

-Put interior back together.

-Get driveshaft built.

-Get exhaust built.