Hi there,
I am a new member and I am looking for advice on the right heads to get for my ls1.
I have brought a high rise dual throttle body intake manifold and 2.5 inch pacemaker headers and have a kelford b12 cam. I want to know what heads would give me the best power increase. I have standard 241 heads. Any advice or ideas would be greatly appreciated
thanks guys

 

What size motor? When you say 2.5 headers are you talking about collector size or primary size? Also, what are your goals? Strip? Street? Combo?

what's your budget?

 

5.7l motor 2.5 inch outlet headers. I want it for street but also want the most power out of it. I don't have all the money in the world. I just don't really understand what it means when they say 205cc or 225cc etc. Just looking for what would get the most power really. Thanks

 

Get the best flowing heads you can afford. Shops back in 2000 were making 500+ RWHP with head/cam kits. And todays heads are way better. Even stock cube engines want to breath a LOT more. They can take really well flowing heads.

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Trickflow as cast 220s will be the best BANG FOR THE BUCK. My buddie just made 495 rwhp with them.

 

Like mentioned before, what's your budget?

 

Numbers like 205 & 225 are the volume of the intake runner in cc.

There's no one "perfect" number; the volume is a function of both the cross-sectional area (which changes from head to head) and the runner length (which is more or less constant for any given type of head), so a 225cc runner would be TINY on a big block with its long runners, but pretty sizeable on this type of motor.

As said, get the best heads you can afford. NOTHING ELSE can "make up" for heads that don't flow. Flow however isn't a direct linear function of port volume, and there's more to head performance than just flow (although flow is probably the single most important measurement); velocity in the port, and proper management of turbulence, are also major factors. You can have a head that flows GREAT, which will then make "the most" power at high RPMs, but doesn't do well at lower RPMs when other factors predominate. Be careful using "most power" as your only yardstick.

Then there's chamber volume, which determines compression ratio in conjunction with the piston design and head gasket thickness. Stock chambers for these motors are in the neighborhood of 70cc; 67 to 71 for various ones, mostly. You probably don't want heads that change that very much from stock; maybe a small bump, but nothing radical. Generally the bigger the cam the higher the required compression. I don't know anything about that particular cam.

 

I would say up to $1000 but could go to $2000 for the right thing

 

I would give Tony mamo a call. His mms223 hesds are a great budget option and flow really well.

 

This is what happens with Tooley TFS 220s with his cam on factory GM rockers.

 

Budget will biggest thing. Pat G made 502whp back in 09 with afr 205 and t rex cam. Through a 12 bolt and 4.56 gears.
another build here made almost 540whp with mamo 220 heads.
Everything will have to match up. Intake, heads, cam etc to make big numbers on stock bottom.

I'd give tsp or btr a call and see what they recommend with current setup you have.

 

nothing that hasn't been done before. Just right combo. Stock bottom ls1 has made 540whp on right setup. And as said pat g made 502whp 9 years ago on stock bottom. Afr 205's

 

I'm quite sure with a 240 plus intake duration cam and afrtermarket roller rockers the tfs would had made 500 plus at the tire as well. The Trex cam is 242/248 duration. The car in the photo is running a smaller 235/242 camshaft with factory GM rockers. The 540 rwhp you speak of is with a LLSR not a hydraulic roller. A solid roller cam even makes a set of LS3 look like Gold on top of the right short block.

 

it should you would think. But combo has to be right.

the t rex car was through a 12 bolt with 4 56 gears. No ewp, heavy clutch. No crabk scrapper. Those little changes to a 10 bolt and added stuff would have made abother 30-40whp pretty easy.

but its all about matching right combos to do what you want.