TXsilverado

iTrader: (18)

i had another thread that got very little attention so im guna make this a poll. ive seen a couple of these threads so im sure yall are tired of seeing them. none of them gave me the answers I need. please dont vote based on what you have, or who gave you great customer service. ive dealt with both companies and both are awesome. im needing to know which head will work best with MY application. what gaskets i need to use, how much compressin do yall think is good etc...heres a copy paste from my other thread.
oh, and THIS IS A LS1!!! NOT A 5.3, NOT A 4.8!!! LS1 LS1 LS1.haha sorry for the disclaimer...it seems every time i post on a car site i get people asking if its a 5.3.

N2DP2QT

iTrader: (13)

get the PRC LS6's

Websy21

iTrader: (34)

Wish I could vote, I am really curious how the 5.3's and the LS6 would match together. Both from PRC have shown great results. Other than the compression difference I am not sure what the big difference is. One guy tells ya to go 5.3 and the next LS6. Good luck on decison. I know I will need it when it comes time for me to decide, haha

aero_ub

I'd also like to know the difference in performance between the LS6 and 5.3 heads...

Websy21

iTrader: (34)

Well I know they have quite a bit difference on runners, etc. I am not a enginerd, just a power engineer, sounds good but I pretty much push buttons, LOL. I'll wait for the 'tech's to chime in.

99wssixm6

iTrader: (3)

This is a very good question. Please guys respond with your decision and numbers to match. We dont always need dyno numbers, it can be seat of you pants feeling alos.....Lets get this going.

Thule

now i only knoiw the patriot heads from own experience, and the are well made, and gave me good power incrase,

compression is 11.1 on my motor

5.3LJimmy

iTrader: (10)

What exactly is your application? What are your cam specs? Do your pistons have valve reliefs? Are you willing to flycut if needed? The flow numbers of all 3 heads are similar, so I would get the heads/gaskets that put my compression and quench where it needs to be. Kinda hard to determine with the lack of info you are providing.

T2SLS1

iTrader: (2)

I have that same Question.I have a trex v2 cam,-2 vr pistons,347 or 408 have not made up mind yet.I like the 5.3 to up compression,But if i go 408 will they be to small.

5.3LJimmy

iTrader: (10)

For a 408 the LS6 heads w/ a 59cc chamber is ideal, and for the 347 the 5.3 heads w/ a 57cc chamber is the way to go. Both of these w/ an .040 cometic gasket.

Websy21

iTrader: (34)

57cc is going to make some serious compression not?

5.3LJimmy

iTrader: (10)

Yeah it'll be 11.7:1 static compression, but w/ a TRex the DCR will be at 8.5. The 408 will have a higher calculated DCR of 8.7 w/ 59cc heads.

T2SLS1

iTrader: (2)

that answers alot i will go with the ls6 because if i go 347 now later i will do a 427 then switch the ls6.How much can i open the the ls6? i want to go 2.08 or 2.10 can that be done on those heads or should i just go dart 225?

TXsilverado

iTrader: (18)

my bad...i copied and pasted the wrong part into the quote of my first post...

99 LS1 (STOCK)
226/226 .584/.584 112+4 XER---TR 7.4's---918's
intake
p&p throttle body
Truck intake manifold
pacesetters/ory/exhaust
asp underdrive/alt overdrive
4.10
A4
3600 stall
FULL BOLT ON

im probably guna spray 125 wet shot through it eventually.

Websy21

iTrader: (34)

Now I am really curious to see what people have to say because I would have pretty close to what you have also

Websy21

iTrader: (34)

I am really surprised on the poll though, because when I was ready to buy before I talked to quite a few and most said the 5.3's for the added compression. I was going to go ahead and get them, than I decided to go FI.

venom ws7

iTrader: (13)

My friend made 359rwhp with small cam full boltons 3.73 A4 3600 Stall
Just PRC LS6 Heads swap made 393rwhp and 28rwtq more (I dont remember the exact numbers on the TQ)

Those PRC LS6 Are freaking awesome get them you wont regret it.
PRC 5.3 Also great set of heads if you get them Mill them for more Compresstion.

Cheater cam and PRC LS6 Heads full boltons a4 = 389rwhp ( No fast setup)
Same car,same cam and same boltons with Patriot 59cc AND WITH FAST INTAKE AND 90MM TB= 395RWHP

Websy21

iTrader: (34)

That sounds like a pretty good gain, decisions, decisions

5.3LJimmy

iTrader: (10)

For that setup the PRC LS6 heads w/ a .040 Cometic gasket would work well 11:1 SCR,8.7 DCR and .032 quench(my vote). The 5.3 heads w/ a stock gasket equate to nearly the same compression, but with a higher .048 quench.

Jason 98 TA

iTrader: (4)

Do a search in the dyno results section bro. I think you'll find the PRC cylinder heads out dyno the competition time & time again.

Here's some resent results I found in the first 4 pages in the dyno section:


----------------------------------------------------------

PRC 5.3l Stage 2.5
MS3 & Fast 90 486rwhp
https://ls1tech.com/forums/dynamometer-results-comparisons/768555-tsp-5-3stg2-5-ms3-vengeance-ported-fast-graph-inside.html

PRC Terminators 490+rwhp
Fast 90 Big Cam
https://ls1tech.com/forums/dynamometer-results-comparisons/760089-ryans-performance-texas-speed-494rwhp-na.html

PRC LS6 233/239 435rwhp
Mustang Dyno
https://ls1tech.com/forums/dynamometer-results-comparisons/670732-dyno-results-tsp-2-5-ls6-heads-233-239-112-2-a.html

PRC LS6 Heads MS3 460rwhp
https://ls1tech.com/forums/dynamometer-results-comparisons/760837-tsp-prc-ls6-ms3-460rwhp.html

PRC LS6 cnc work & camshaft
Added On Stock LS6 Motor
https://ls1tech.com/forums/dynamometer-results-comparisons/761824-dyno-d-new-setup.html

Independent dyno results are definately the best method for checking a products true power potential. The dyno results section is your best friend when searching for new parts!