Engine swap help...

[Sean Buick 76]

So swap in the 6.0 and then build the 5.3 Gen V for a turbo and swap it in later. Use a Elgin sloppy stage 2 cam, matching lifters and trunion upgrade.

 

[0xDEADBEEF]

The new 5.3L is a DOG plain and simple. Peak torque of only 383 ft/lbs @ 4,100 from a direct injected engine is terrible in 2014 much less 2024. The 2.7L 4 cylinder will destroy the 5.3L in every possible metric. I would expect much more especially in 2024. Hell I drove a 2012 Titan that made 388 wtq @ 2,980 rpm at the tires on a Mustang dyno with an Airaid MXP4 intake, magnaflow and a generic Hypertech tuner on it. That was an 8 year old engine design at the time as well and it kicked a 6.0L around in the power department much less a 5.3L.

Whatever dude. When the hallowed L31 is at its peak torque, the L83 is making MORE torque. It makes the L31's peak torque 800 rpms sooner.

It's in no way a downgrade. I feel like I'm talking myself into an LT swap.

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[smdk2500]

Whatever dude. When the hallowed L31 is at its peak torque, the L83 is making MORE torque. It makes the L31's peak torque 800 rpms sooner.

I feel like I'm talking myself into an LT swap.

LT or LS? If you want a LT I have one in a firebird you can buy lol. It comes with the whole car attached.

 

[0xDEADBEEF]

LT or LS? If you want a LT I have one in a firebird you can buy lol. It comes with the whole car attached.

LT. Gen V LT, specifically. I had a 99 Trans Am. Loved that car.

 

[smdk2500]

LT. Gen V LT, specifically. I had a 99 Trans Am. Loved that car.

I'm to big of a guy to fit the car. its hard to get in and out of and the seat hugs me a bit to tight lol.

 

[0xDEADBEEF]

I'm to big of a guy to fit the car. its hard to get in and out of and the seat hugs me a bit to tight lol.

Yeah, I was probably 80 lbs lighter back then. Trying to get back there.

 

[L31MaxExpress]

Whatever dude. When the hallowed L31 is at its peak torque, the L83 is making MORE torque. It makes the L31's peak torque 800 rpms sooner.

It's in no way a downgrade. I feel like I'm talking myself into an LT swap.

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Here is a stock L31 chart once the garbage factory tuning is gone. This one had a 7395' cam and marine intake but the stock camshaft and manifold are really not costing it much in the way of torque or power. The L31 is making more torque at 2,500 rpm than the L83 makes at peak. With 1.6 rockers and the short runner Ramjet intake the Ramjet 350 makes just as much peak HP as well. I have tuned a Ramjet 350 on the chassis dyno and it made more power everywhere than a L83 truck did. At 2,500 rpm the L83 was not even within 50 ft/lbs of the Ramjet or basic L31 with a tune. It is not even hard to make over 300 wtq with a 350 TBI.

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[Cadillacmak]

Here is a stock L31 chart once the garbage factory tuning is gone.

I like that torque curve!

 

[L31MaxExpress]

Here is a crank dyno of a Ramjet 350. 7395' 196/206 @ 0.050 cam, 1.6 rockers and 1-3/4" long tubes but otherwise it is a stock L31 350. ~390+ tq from 2,500-4,900 rpm. Could not ask for a better torque curve doing truck things. My 383 has a similar torque curve but nearly 100 ft/lbs more across the whole RPM range. At 5,000-5,100 where the stock L31 WOT shift point is the Ramjet 350 is still making ~364 hp.

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[L31MaxExpress]

I like that torque curve!

The intake manifold used on the Ramjet 350 combined with the 1.6 rocker does even better than the long runner truck/marine crossram manifold.

I gained over 40 ft/lbs at the tires across a broad RPM tuning a stock L31 350. At 1,500 rpm it gained 60 ft/lbs. It knocked over 2 seconds off the 0-80 acceleration time.