1998 5.0 Vortec swap to 1999 LS 4.8 vortec

[Sean Buick 76]

The LS engines need a proper tune, and long tube headers to show thier worth. A mild cam is a 80 HP upgrade.

 

[L31MaxExpress]

The LS engines need a proper tune, and long tube headers to show thier worth. A mild cam is a 80 HP upgrade.

Mild cam in a L31 350 is a similar gain. The OE Vortecs actually outflow the Gen3 4.8/5.3L heads stock for stock. A SBC sees better gains from a set of headers than a LS does. I have had small blocks gain 40+ TQ with headers.

 

[Supercharged111]

The LS engines need a proper tune, and long tube headers to show thier worth. A mild cam is a 80 HP upgrade.

?? No. A mid sized cam in my C5 Z06 will get me around 40hp.

Here's how a 4.8, 5.3, and 6.0 stack up to a 454.

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Where the 4.8 shines is under boost. Apparently you can just crank the boost to the moon, well past where a stock 5.3 or 6.0 can hang on, because of that short stroke. Somehow the rods just hang on better.

 

[Sean Buick 76]

Mild cam in a L31 350 is a similar gain. The OE Vortecs actually outflow the Gen3 4.8/5.3L heads stock for stock. A SBC sees better gains from a set of headers than a LS does. I have had small blocks gain 40+ TQ with headers.

Wow that’s impressive thank you for the information! Have you ever tried vortec heads in replacement of the TBI heads, a carb intake and an adapter plate for the GM EFI? I would like to figure out how to do a dual TBI setup!

 

[L31MaxExpress]

Wow that’s impressive thank you for the information! Have you ever tried vortec heads in replacement of the TBI heads, a carb intake and an adapter plate for the GM EFI? I would like to figure out how to do a dual TBI setup!

I have on a performer rpm and a vic jr manifold using a 2" bore TBI. I have done the dual TBI setup on a tunnel ram on a solid roller 406 with AFR eliminator 210s. There are several companies offering Peak and Hold injector driver amplifiers int the $200 range that will allow a TBI ECM to drive 4 TBI injectors correctly. The 93-95 TBI Automatic transmissiom PCMs have fuel and spark tables to 6,400 rpm and can handle a good bit more rpm, but the injector pulsewidth will be fixed at whatever it was in the 6,400 rpm VE table cell. The system will drift a little rich over ~6,400 but we were cranking that 406 to 7,200.

 

[Sean Buick 76]

I have on a performer rpm and a vic jr manifold using a 2" bore TBI. I have done the dual TBI setup on a tunnel ram on a solid roller 406 with AFR eliminator 210s. There are several companies offering Peak and Hold injector driver amplifiers int the $200 range that will allow a TBI ECM to drive 4 TBI injectors correctly. The 93-95 TBI Automatic transmissiom PCMs have fuel and spark tables to 6,400 rpm and can handle a good bit more rpm, but the injector pulsewidth will be fixed at whatever it was in the 6,400 rpm VE table cell. The system will drift a little rich over ~6,400 but we were cranking that 406 to 7,200.

That is very cool I didn’t know that they sold parts to facilitate dual TBI, it would work well I think! I don’t want to derail this thread but if you are interested in sharing more info about the dual TBI send me a message?

 

[0xDEADBEEF]

?? No. A mid sized cam in my C5 Z06 will get me around 40hp.

The LS6 cam is basically already a mild cam so you have less to gain.

 

[Supercharged111]

The LS6 cam is basically already a mild cam so you have less to gain.

There's no way you're getting 80hp from a cam swap without going nuts.

 

[0xDEADBEEF]

There's no way you're getting 80hp from a cam swap without going nuts.

Holdener has some videos on it. I don't recall the numbers. He doesn't measure with accessories and obviously uses an engine dyno.

My heads cam LS6 made something like 440 on a hub dyno. Gave the sheet to the new owner, so just going from memory.

 

[0xDEADBEEF]

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