SPOOLIN Z28

Any sponsors have any good deals going on for a set of gmpp Cnc ls3 heads? Looking to give my ls3 a little upgrade. I figure I can sell my stock ls3 heads and not be in a set of new heads for too much.

G Atsma

You might do better with Texas Speed and Performance's LS3 port job. Their flow #'s beat GM's while keeping port volume less, which promotes better velocity.
Plus they will do YOUR heads for about $750/pr. plus any different springs or valves.

big hammer

They'll make some zoot but really need rpm to utilize them on a 6.2

G Atsma

True, I just figured if he's doing heads, might as well get some that will be a bit better on the low/midrange than the GM heads.
IMO, a stock or near stock LS3 does not benefit from bigger ports. You might gain 10-15HP, but at what cost?
Now if a big cam is involved, then yeah, get some bigger ports to support the cam. Or to put it the other way around, if you get bigger ports, get a bigger cam to feed those ports!

KW Baraka

iTrader: (7)

I would do a cam upgrade before I did a head upgrade. A lot more to be gained with more cam.

Point of fact; the three LS3 crate engines (430 HP, 495 HP, and 525 HP) are EXACTLY THE SAME.....except for different cams. And of course, they all have stock LS3 (OEM) heads.

http://www.chevrolet.com/performance/crate-engines/ls3

http://www.chevrolet.com/performance...ines/ls376-480

http://www.chevrolet.com/performance...ines/ls376-525

Just an example of what a well spec'ed, medium size cam can do with these engines.

Best of luck!

KW

G Atsma

WORD! You have plenty of capacity in your present heads. A cam will wake up your engine WAAAY more than heads would, as KW says above

99 Black Bird T/A

iTrader: (4)

One of those spiffy Radius Rod modified LS3 intake manifolds would likely help the LS3 stock heads pick up as much hp as the GMPP ported heads for a fraction of the cost.

G Atsma

I would imagine the radius rod manifold and a mild cam would really kick it up a few notches.
We have flow tests, but has anyone dyno'd a stock ls3 with and without the radius rod mod? Or any cam, as long as the test compares the manifolds ONLY to make it unbiased.

SPOOLIN Z28

Engine has a Tsp 231/236 cam and Vic jr intake and 4150 tb

Joeking1025

iTrader: (1)

I would like to see a dyno with the stock ls3 vs the cnc version on an ls3 with a decent cam to see the difference. I think there was a articles comparing the two but it was in a stock ls3 and the cnc were good for an additional 10 horsepower

Papermachtech

[QUOTE=KW Baraka Point of fact; the three LS3 crate engines (430 HP, 495 HP, and 525 HP) are [B]EXACTLY THE SAME[/B].....except for different cams. And of course, they all have stock LS3 (OEM) heads.

This is from the GM site for the 525 hp ls3;
The ASA camshaft is a hydraulic roller with .525-inch lift on both sides, along with 226 degrees duration on the intake side and 236 degrees on the exhaust side. And for durability, we complement the cam with higher-rate valve springs.

KW Baraka

iTrader: (7)

I'll believe that when they list a part# for those 'new' springs. What I do know is that when that crate engine was first released (and until recently anyway) they came with the same springs as the OEM LS3.....

KW

KW Baraka

iTrader: (7)

10 HP for a new set of heads costing $1000+.....versus up to 70hp for a well spec'ed cam and new springs. Don't need to be a rocket scientist......

KW

G Atsma

Yeah, the old HP/$ ratio doesn't quite pan out on that one.... You can get much more for much less...