5.3 and LS1 heads

Hippiehead025 · October 24, 2004

are they the same? like the actual body of the head, not its internals....i know springs and rockers r different. and were the 5.7 LS1's avaialbe in our trucks? ( 04 Silverado/Sierra)

The SPEEDY · October 24, 2004

The combustion chambers of the 5.3's are smaller than ls1's. So if you put ls1 heads on your truck it would lower your compression ratio. You wouldn't see any beneffits from swapping from 5.3's to ls1's. As far as flow numbers I'm not sure, I know that some of the better (higher flowing) aftermaket ported heads are 5.3 castings. No 5.7's were not available in any trucks.

Hippiehead025 · October 24, 2004

The combustion chambers of the 5.3's are smaller than ls1's. So if you put ls1 heads on your truck it would lower your compression ratio. You wouldn't see any beneffits from swapping from 5.3's to ls1's. As far as flow numbers I'm not sure, I know that some of the better (higher flowing) aftermaket ported heads are 5.3 castings. No 5.7's were not available in any trucks.

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so is the 5.3 engine basically a destroked LS1 with higher Cr.?

99Silver6.0 · October 24, 2004

LS1 guys love P&P 5.3 heads. Speedy you can vouch for that cant ya? Kicks the compression up on an LS1. TO what I cant really remember.

zippy · October 26, 2004

the combustion chamber is smaller and the intake valve size is smaller. the 5.3 is a smaller bore with the same stroke as the 5.7 gen III engine.

The SPEEDY · October 26, 2004

LS1 guys love P&P 5.3 heads. Speedy you can vouch for that cant ya? Kicks the compression up on an LS1. TO what I cant really remember.

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Yep, thats the setup to go with on a ls1. As far as comp. ratio I'm not sure but I want to say 11:1

If you ask me, there are way to many directions you can go when it comes to modding these ls1 and ls1 based engines. Not that it's a bad thing, just makes for some really tough decisions.