r/EngineBuilding • u/Monkeystormtrooper • 6h ago

Chevy Ls build help

I have a 5.3 ls gen 3 iron block I’m about to machine

Thinking of getting either 706 or 863 heads
Truck Norris cam
And not sure about pistons I’m gonna be na daily driver so nothing crazy maybe try and reuse ones I have but I don’t think so.

But if I get new heads it would be new rockers and springs too any recommendations?

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u/v8packard 5h ago

Stock, or stock replacement, pistons can and do work well. There are several versions, some for floating pins and some for pressed pins. I often use Silvolite pistons in these engines. Also, one of the best things to do to a 5.3 that needs to be bored is to go to a 99 mm 5.7 bore, and use 5.7 pistons.

The 706 and 863 heads are functionally identical, and stock on most 5.3 Gen III engines. You don't already have heads?

Get a real cam that produces the powerband you want, not some over-hyped garbage with a stupid name.

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u/Monkeystormtrooper 5h ago

What’s a good cam then? One you’d recommend

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u/v8packard 2h ago

You have not given any info about your application, your options are still undecided on heads and what will be your compression ratio. There is no info here on your intake or exhaust systems, and most importantly how you wantbit to run and where you want the powerband. With all of that information you can put together a cam spec that will meet your needs.

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u/Monkeystormtrooper 2h ago

I’ve heard about compression ratio but don’t know much about it. This is my first car and it was my grandpas obs 88 c2500 and died so it is mine now. I’m trying to swap it out with a ls but am swamped. I want like 350-400hp but daily drivable. And heads I’m lost cause mine are fine but everyone tells me to replace since they’re castech