Mr_president

iTrader: (38)

Ok guys well my motor has a compression of 8 to 1 with 72cc chamber heads. I have been watching and it seems the new sweet spot is 9:0 to 9:3 . If i use thise 63cc heads it will put me right around 8.9 to 1 which I lIKEY, do you all think the deck is to thin?? I was going to go with ls6 heads that are 64cc chamber heads to put me at 8.7
thanks ahead of time!

Websy21

iTrader: (34)

You already know what I think, 243's and 8.7 CR dumdumdum

Mr_president

iTrader: (38)

wow that was fast lol....well I just came across some 5.3s for trade with my 317 heads I just want to make sure they'll work on the 370 and they flow pretty good but I dont see how its better to go from 5.7 heads to 5.3 heads it confuses me a little bit

ninetres

iTrader: (35)

Do you ever listen to me? They will be just as safe as one-and-another as long as one of them is not milled. Are the 59cc chambers oem spec?

Websy21

iTrader: (34)

I can't remember since its been I while I researched both heads but I do believe the LS6 heads flow a bit better than the 5.3's. The reason many go with the 5.3's over the LS6 heads is for the added compression in N/A applications.

I am sure either one will do fine, but you hear of the LS6 heads more so in FI than the 5.3's

Like Nitress said, as long as they are not milled and oem spec. The LS6 heads are around 64cc but can't remember what the 5.3's are. They are lower thats for sure, just how much though?

Mr_president

iTrader: (38)

yea that was my main question to if 63 cc is oem spec on the 5.3 ill go do some more research, I was also wondering if anyone had a problem of lifting any heads with the 5.3s, sean i listen to you but there is nothing wrong with getting other people's opinion on things...ya dig

Websy21

iTrader: (34)

Ok, that took 10 seconds................since you are lazy, LOL, I looked it up for ya it was about what I thought they were. Stock are 61cc for the 5.3's, don't run them unless they are the ported one's IMO. I'd still go with the ported LS6 one's myself but I am sure the 5.3's will suffice. Not sure about the decking though, for that you will need to LOL

Mr_president

iTrader: (38)

well i did some research as well there are several different 5.3 castings I'm kinda scared to use 5.3s on a 6.0 lol but there unmilled and 61cc love it!! uhhh what casting where on those that you found?

Mr_president

iTrader: (38)

bump no one else

cws T/A

iTrader: (3)

How about LS6/LS2 243's with a .040'' thickness headgasket .

Mr_president

iTrader: (38)

thats also what i was thinking would milling the head 5 thousands 1cc be that big of a deal for boosted aps? Are the .040 mls cosmetic gaskits ok?

ninetres

iTrader: (35)

Milling the head 1cc will make no noticeable difference in performance......so wtf would someone do that for?