421 stroker prc 2.5 5.3 heads vs stock Ls3 heads?
#1
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421 stroker prc 2.5 5.3 heads vs stock Ls3 heads?
What would make more power on a 421 stroker, the 2.5 5.3 heads with a ported fast intake, or ls3 heads and intake unported?
#7
Alot of people on the Corvette fourms say the LS3 intake isnt even worth porting. There was an article where one didnt gain any power. Seems like everything on the LS3 is beast out of the factory lol
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#12
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Yeah, I agree. To me it's a no brainer. You can put on the already ported 5.3's which leaves you really no more room for more, or opt for the LS3's, which are going to be right there with the ported 5.3's, but you have room to grow my having them ported down the road. Plus, you don't have to pay a kings ransom for a FAST intake/TB setup because the stock LS3 intake is already pretty killer.
#14
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Yeah I was thinking the LS3's might be better,I just already have the ported fast and the prc 5.3 heads. I guess my follow up question would be how much better would the LS3's be?
#15
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In regards to how much better the LS3 setup will be, my guess would be 5 to 10 maybe, but the main selling point should be for future power. Like I said, CNC porting the LS3 heads would be worth a lot more in the future.
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Depending on your future goals I might just consider using the 5.3 setup since you already have it. With the money saved you could add some nitrous or do some suspension or appearance mods, or whatever
#17
I just went from Stage 2.5 5.3 heads to LS3 heads. In between I went 9 inch rear and 3.5 inch driveshaft (+2lb rotational weight).
Pre 9 inch rear: 372ft/lb 419 HP
9 inch rear (-torque/hp) + LS3 top end: 405/430.
If you consider the 9inch to eat up 3-5% more power, the gains are a lot more than what the numbers indicate.
Pre 9 inch rear: 372ft/lb 419 HP
9 inch rear (-torque/hp) + LS3 top end: 405/430.
If you consider the 9inch to eat up 3-5% more power, the gains are a lot more than what the numbers indicate.
#19
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I just went from Stage 2.5 5.3 heads to LS3 heads. In between I went 9 inch rear and 3.5 inch driveshaft (+2lb rotational weight).
Pre 9 inch rear: 372ft/lb 419 HP
9 inch rear (-torque/hp) + LS3 top end: 405/430.
If you consider the 9inch to eat up 3-5% more power, the gains are a lot more than what the numbers indicate.
Pre 9 inch rear: 372ft/lb 419 HP
9 inch rear (-torque/hp) + LS3 top end: 405/430.
If you consider the 9inch to eat up 3-5% more power, the gains are a lot more than what the numbers indicate.