I have a 81 malibu I have talked about on the site before and I am trying to make it a sleeper out of it I have thought about upgrading the 3.8 v6 in it as of now but I was wondering if swapping to a 5.3 vortec would be a good idea because vortecs are reliable, powerful, and cheaper than a lot of stuff so if I did this how would I because there is so much computer involved? Would swapping for a vortec work
Seeing that you’re just dreaming
Why not just get a ZZ632/1000 crate motor and drop it in ?
632 cu.-in., 1004 hp, 876 lb.-ft. of torque on 93-octane pump gas
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If you’re going to do this . . .
I highly suggest talking to people or shops that have already done that exact swap
And you’ll need to either buy a ready-made wiring harness . . . or have one custom-made
But I’m worried you’ll wind up with a car that you’ve sunk a lot of money into which doesn’t even start or run
By the way, I recommend AGAINST the 5.3 . . . too many issues, imo
The 6.0 liter is MUCH simpler and more reliable
6.0-liter backed up by a 4L80E
Does your 1981 Malibu currently run?
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You will also have to upgrade the chassis and brakes. Dropping a V-8 in where a 6 was may result in the front end dropping onto the hard stops. You’ll need to upgrade the springs to ones meant for a V-8 Malibu. And then think about brakes. Starting is optional, stopping is mandatory.
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4.8, 5.3, and 6.0 were all the same block until 2007. None of them had more or less issues than the other. 5.3 didn’t get cylinder deactivation until 07. Some 6.0’s got it around that time also, but not in 3/4 ton trucks.
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Plenty of info on the web about doing this swap. You need the wiring harness and ECM out of the donor vehicle with the 5.3. Biggest issue, in my opinion, is going to be figuring out how to get the gauges and all that extraneous stuff to work, but it’s done a lot. Guy at work has an early 80’s truck with a 6.0 ls swapped in. Have an acquaintance with an old Dodge D100 with a 5.3.
Guy that works at a local shop has a 6.0 swapped 1993 k1500 Silverado, also. He is a mechanic, though. Would be above my skill level, I think. But, it’s done all the time.
Just to clarify… Not a Vortec, this would be an LS swap. A carbureted Vortec would be easier. Both require new, stronger transmissions.
A 2007 or earlier 5.3 and 4L60 swap would be the cheapest but a LOT of things are needed to make it run properly as previously mentioned. Wiring harness and computer. A flash for the ecu would be required. A complete fuel pump, regulator and return system. Gauges as none of the old ones will work, including speedometer. The transmission tunnel still needs hammer work. A custom driveshaft is required.
A lot of work but you’d have a modern fuel injected engine pumping out 295 hp and 335 ft-lbs of torque. 3 times your 6.
I think “Vortec” is kinda, sorta like “Hemi”. It doesn’t refer to a specific engine. A 5.3 liter is a “Vortec 5300”.
Most people refer to the last 350 as a Vortec. I think that is what you were thinking.
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Or…you could even do a carbed ls (5.3, 6.0) and skip the wiring and computer, I assume. Would have to use a 700r4 (otherwise referred to as a 4l60) trans (basically a non electronically controlled 4l60e). Or a turbo 350 or turbo 400, but you’d have no overdrive unless you used the 700r4. I could be talked into losing fuel injection in an 81 Malibu project, but I’d want overdrive.
All in all, might be more cost effective to sell your Malibu Classic and locate a classic Malibu that already has a 327, 350, or 396 in it.
Who knows, if you want a sleeper you might find an ex-HWP 2 door plain brown wrapper.
At that point, a Gen 1 V8 Chevy makes a simpler swap, I’d think. A 350, 383 or even a 400 in front of a 700R4 non E version would be as close to a bolt in as possible. Even the engine mounts bolt right up. Aluminum heads, manifold, and water pump plus headers would get the weight close to the all iron V6. Add a big 2 row aluminum radiator to keep it cool.
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Can we all agree to AVOID the 5.3 with active fuel management . . . ?
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Yes sir.
Plus a few characters to get over ten.
Heck YES!.. 10 char!
A donor 4.8 liter LS and 4L60E out of a 1500 Silverado should be doable, and not too over-the-top, while still being a heck of an upgrade over a 1981 3.8 V-6 
Yes my car is running and can drive but doesn’t have a freeze plug so I haven’t moved it without a trailer
I was thinking because I had a 350 I was gonna swap but the engine is seized that instead of that I could swap for a 5.7 that I have ( if it’s good ) from a 96 seirra and then Put a carb on that then I would have a 350 with the Potential to be a ls
A 350 IS a 5.7. 350 cubic inches is 5.7 liters. But an LS is a later TYPE of Chevy V8 and parts don’t readily interchange between the 2. You need to read up on this stuff before you start this build or you will never pull this off.
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You were right! He meant Vortec as in 96-99 350.
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