Flow and Runner Spec's for Stock 5.3L Heads

[SS Killer]

Does anyone know what a stock 5.3L head flows? Is there a chart out there somewhere that specs all this info?

[SoHo48]

i saw it on a web page once hang on ill look it up

[SoHo48]

i was on a vendors page damn,... it had a comparison from stock heads and ported heads. ported, 862's flow good enough for 450+ hp n/a.. i would go with 5.3 if your going f/i because the chamber is so small.

[SS Killer]

i was on a vendors page damn,... it had a comparison from stock heads and ported heads. ported, 862's flow good enough for 450+ hp n/a.. i would go with 5.3 if your going f/i because the chamber is so small.

yea, with that chamber and -28cc pistons I'm looking at a CR of 9.5 on a 6.7L.

With -2cc pistons I'm at 11.5-12cr which would be nasty power in a N/A set-up but only if I have the flow I need.

Could I port them to support 700 HP N/A?

[SoHo48]

yea, with that chamber and -28cc pistons I'm looking at a CR of 9.5 on a 6.7L.

With -2cc pistons I'm at 11.5-12cr which would be nasty power in a N/A set-up but only if I have the flow I need.

Could I port them to support 700 HP N/A?

your pushing it.. your going to need a big stick and a lot of timing to get 700n/a unless you plan on getting 400 from the motor and 300 from the bottle....

[SS Killer]

your pushing it.. your going to need a big stick and a lot of timing to get 700n/a unless you plan on getting 400 from the motor and 300 from the bottle....

I'm lookin at another set of heads... ported L92's that flow a lot more air than the stocker's. I'm going to have to ditch my 5.3 heads if I'm going to make any kind of power at all.

I'm looking at a 228/232 cam with 114 LSA and right at .600" lift. 1.85 rockers and the 2.165" intake valves on these heads will give me something like 356 cfm of flow. This set-up should get me somewhere north of 700HP at the motor and something like 600 RWHP.

Only babies feed on bottles.

[SS Killer]

Does anyone know what a stock 5.3L head flows? Is there a chart out there somewhere that specs all this info?

Great info on stock LS1's!

[Slimsilverado]

Remember the L92 heads wont fit on a 5.3 block bore is 2 small!!!

[PurpleMinivan]

Remember the L92 heads wont fit on a 5.3 block bore is 2 small!!!

Read it again... he's talking about a 6.0L I would hope, cause you can't bore a 5.3L to a 6.7 without paper thin walls.

[SS Killer]

Read it again... he's talking about a 6.0L I would hope, cause you can't bore a 5.3L to a 6.7 without paper thin walls.

This is what I'm basing this entire build on. 5.3's are out... i'll sell them to offset some of this cost...

I'm planning on reusing the stock intake manifold and an 85mm TB... see any problems there?