5.7 carb or 5.3

[Chad]

What would I be better off getting? I want around 450 hp but idk what would be better

 

[Chad]

I have a vortec now

 

[k_pro1992]

i would do a ls swap and build a 6.0.

 

[Aloicious]

LSx over a carb any day of the week....you can get 450hp either way, but I'm a MPFI kinda guy...to me going carb is like taking a step backward, MPFI offers alot of benefits, but can be a little more complex than carb, so to each their own.

 

[Fobroader]

5.3 or 6L for sure. Theres a reason that the carb is dead, how can you disagree with the LS' power, reliability and tunability???

 

[90lsx]

6.0 some head work. A good cam selection and you're good to go guaranteed horsepower reliable and the tuning software out for the Lsx motors is ridiculous. Just my. 02

 

[Chad]

Is there a big price difference?

 

[DRAGGIN95]

Yes please don't put a carb on it, LS motor all the way!

 

[SubLo]

For a 5.3 to make 450hp, it would be unstreetable. You'd be torturing yourself as a DD. Reason being, you'd have to choose a crank, piston, and head combo to put you in the @10.5 - 11:1 or greater compression ratio with all sorts of supporting mods like 4-bolt main, 750 - 800 cfm carb or equivilent efi, raised runner/intake, high-pressure fuel pump, blueprint/balance, and relatively large/lopey/poor-street-idling cam, etc. Otherwise, a supercharger might put you close to there on a more or less stock 5.3.

The 5.7 with it's slightly larger displacement could put you there with an ever so slightly lower compression ratio albeit with extensive mods as well.

If you're looking at a brand new long-block swap and are shooting for that power level, i'd look at a 406 (bored/honed 400) for streetable power.

That's my 2 cents. Other opinions may vary.

<flame_on>

 

[silverado_lover]

For a 5.3 to make 450hp, it would be unstreetable.

Wrong, forced induction.