5.3 heads vs 806 heads
09-02-2009, 11:24 AM
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5.3 heads vs 806 heads I was searching through some threads and found some flow numbers on different heads. After looking through a few threads, it seems that the 5.3L heads are pretty much identical in flow numbers to the different LS1 heads.
What was interesting is that the 5.3L heads have almost the same flow #'s as the LS1 heads with a smaller intake valve diameter. My question is, what can be done to increase the flow #'s on those 5.3L heads to flow more on par with 243's without spending too much money?
I can find a set of 5.3L heads dirt cheap and was thinking about dropping some larger valves in there, mill them to bring up the CR, and then clean up the castings. Would this be cost effective at all? Spending big money on some heads isn't even an option; should I just save for some 243's?
BTW- I have 806 heads and I know they don't flow that great compared to the other LS1 castings but from what I've read its not worth swapping even 241's for the few extra CFM. This is not my daily but the wife doesn't approve of spending loads of cash on the car since it's just in the garage.
What was interesting is that the 5.3L heads have almost the same flow #'s as the LS1 heads with a smaller intake valve diameter. My question is, what can be done to increase the flow #'s on those 5.3L heads to flow more on par with 243's without spending too much money?
I can find a set of 5.3L heads dirt cheap and was thinking about dropping some larger valves in there, mill them to bring up the CR, and then clean up the castings. Would this be cost effective at all? Spending big money on some heads isn't even an option; should I just save for some 243's?
BTW- I have 806 heads and I know they don't flow that great compared to the other LS1 castings but from what I've read its not worth swapping even 241's for the few extra CFM. This is not my daily but the wife doesn't approve of spending loads of cash on the car since it's just in the garage.
09-02-2009, 11:46 AM
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I was considering that!!! A friend has some 5.3L heads off his truck and he said he'll give them to me for a burger and fries LOL!!! I wanted to swap in some larger valves and mill them but IDK if its worth it.
09-03-2009, 11:08 AM
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you will gain some power/tq from the compression bump alone....have the 2.0 intake valves from your ls1 heads put in the 5.3s with a nice multi angle valvejob,and you should see a nice gain...
09-03-2009, 03:16 PM
#7
You can use the stock intake seats and have them cut for the 2.0" intake valve. The exhaust valves are the same 1.55" for LS1 and 5.3. But by the time you spend the money for someone to cut for the new valves and valve job you'll be close to 243/799 casting money. You should be able to find a takeoff set in the $400 range.
