DANSBIRD

iTrader: (2)

Timing chain snapped & my valves are wiped out and I'm considering just replacing both heads and putting on some complete 5.3L heads.


Thoughts? Bad idea?

Stocktonz28

I wouldent do it....

But then agian it all depends on the size of the vavles.
depending on whatcha buy you could end up losing alot of power.

Besides theres not much of a price diffrence.

If the intake and exshust are smaller then your going to lose power and your motor wont work to MFG Specs.

If you dont mind the power cut and they fit properly go for it but say good bye to your fuel econmey its gonna drop with lesws air intake and harder to push out exshust from your combustion chamber

Stocktonz28

Stock LS1 Heads
Chamber 66.67 cc 0.100 0.200 0.300 0.400 0.500 0.550 0.600
Intake 200 cc 67 122 178 215 219 223 227
Exhaust 70 cc 52 97 133 156 170 176 180
Valve Diameter Intake 2.00"
Valve Diameter Exhaust 1.55"
Part Number 12559853 (1997-98)
12559853 (1999-00)
12564241 (2001-03)

hope this helps.

As long as the 5.3 heads meet these specs or exceed them you should be fine but if there lower then go for a set from Texas Speed or anyone else who has a nice set of alumnuim heads for a reasonable price.

DANSBIRD

iTrader: (2)

The 5.3L heads should raise the compression, at least that's what I was told. Reason I'm looking at the 5.3 is b/c I can get them for under $200.

kmracer

iTrader: (1)

if you wanna stick with stock heads, the 5.3's would be a good option IMO. are you looking for ported heads or just something to get the car driving? are the pistons still good?

Stocktonz28

dont go below these specs for the valves

Valve Diameter Intake 2.00"
Valve Diameter Exhaust 1.55"

and you should be good. Air flow is vital. No point in having higher CCs if you cant fill your combustion chamber with air or get nearly all of the exshust fumes outta your combustion chambers

But dude in all honesty if its a daily driver get em for 200$s to last you for now. Also while your in there like the other guy said do another run over on your motor make shure nuttin else is jacked up to man

slt200mph

iTrader: (42)

A set of TEA 5.3 stage 1.5 heads will make plenty of power and you can mill them .030 and bump that compression up too.

bjamick

iTrader: (31)

the 5.3 heads flow just about the same as ls1 heads. You do get the bump in compression also. A good bump I might add, I believe with just the heads you will be sitting around 11.1:1. Now if you want to add a cam you will definitely have to watch out on how big you go.

BlackTA96

iTrader: (3)

So would slapping on a set of stock 5.3 heads onto a ls1 be a good thing to do?

ramdaspadhye

iTrader: (3)

Better than stock 241's, yes. Get em ported from one of our sponsors! I think TSP was wanting somewhere in the neighborhood of 600 bones for a cnc job on them

NemeSS

iTrader: (127)

not stock, if they are heavily worked, of course.
a set of 243 or 799's will make a better option even stock and will raise scr as well

MUSTANGBRKR02

iTrader: (91)

Yes but he is going for price.

slt200mph

iTrader: (42)

I would not bolt on a set of stock 5.3 heads .... it is not worth the time and money for a minium power gain....now a set of CNC ported heads with 2.02 intake valves and 1.57 exhaust valves is a different story.

LS1Formulation

iTrader: (13)

Stock 5.3 heads with no work will give you a little more torque and lower your top end power due to smaller valves/less total flow. Not really worth it unless you port the bowls and install larger valves.