Getting LS6 heads ported
Properly ported #243's with a valve job and milled you'll get 40rwhp to 50rwhp gains over as cast.
My ported WCCH #241 heads gained approximately 32rwhp over stock. With a 232/236/113+ CamMotion cam (which is good for about 50 rwhp). My LS1 MN6 with 4.10s made 418rwhp/388rwtq. With L6 intake, ported stock TB, long tubes and a Vararam.
Those same WCCH heads with 228/228/112 TSP cam (which is good 45rwhp), 4.10s, L6 intake, stock TB, BBK shorties and a Vararam made 391rwhp/379rwtq.
So yes...you'll see more than 15 to 20rwhp gains out of properly ported stock heads.
This will also help clarify for you:
http://advancedinduction.com/LSX/AiL...cGMLS2Head.php

Properly ported #243's with a valve job and milled you'll get 40rwhp to 50rwhp gains over as cast.
My ported WCCH #241 heads gained approximately 32rwhp over stock. With a 232/236/113+ CamMotion cam (which is good for about 50 rwhp). My LS1 MN6 with 4.10s made 418rwhp/388rwtq. With L6 intake, ported stock TB, long tubes and a Vararam.
Those same WCCH heads with 228/228/112 TSP cam (which is good 45rwhp), 4.10s, L6 intake, stock TB, BBK shorties and a Vararam made 391rwhp/379rwtq.
So yes...you'll see more than 15 to 20rwhp gains out of properly ported stock heads.
This will also help clarify for you:
http://advancedinduction.com/LSX/AiL...cGMLS2Head.php

228/228/112 with ported 241's
232/236/113+ cam with ported 241's (software glitch screwed up the printout and I spilled water on it)
Above examples to show the gains a well ported 241 can make. My machine shop could have gone even further with them but I only wanted to pay a couple bucks to have them retouched.
I had mine ported in 2003 for $1200 with upgraded springs I was in for $1700. I still run them 20 yrs later (new BTR springs) with boost.
I saw a minimum of 32rwhp out of ported 241s twenty years ago. CNC programs today are more advanced. Getting on average 8 more rwhp out of them.
So "opinions" above stating 15 to 20rwhp are totally incorrect.












