Sladester2

iTrader: (1)

Right now I have stock 853 heads with a btr stage 4 cam.. So a large cam. I run 7.2 @94 on average in the 1/8th mile.. What should I expect if I went to ported 243s in et gain and hp gain?

one fast zo6

iTrader: (490)

might run a 7.0

HCI2000SS

iTrader: (2)

Depends on who ports them but a good ported 243 head would probably get you a good 40 hp or so

Sladester2

iTrader: (1)

Thanks guys, not sure 2 tenths is worth it to me for the cost and work

kinglt-1

iTrader: (26)

I bet you gain more then 2 tenths.

wannafbody

iTrader: (2)

Texas Speed stage 1 costs $750. If you don't have the 243 heads you can always get your 853's ported. I still have the stock cam and the ported 243's were an improvement on the street. I'm not sure how much hp I gained but the car is definitely more fun to drive.

99 Black Bird T/A

iTrader: (4)

I think Advanced Induction has one of the best overall 853/241 ported cylinder heads. They says a 346cid LS1's can manage 440-470rwhp with their welded up high compression 852/241 heads. They also say that their best ported 243/799/LS6 head are capable of with most LS1 & LS2's producing 450-500rwhp.

Based on supporting mods the properly ported 243/799/LS6 head is probably worth 10 hp to 30 hp over the the best ported 853/241. Most ported 853/241 heads are not welded to boost compression. The average ported 853/241 isn't going to make 440 to 470whp.

There is a lot of interesting reading here...
http://www.advancedinduction.com/LSX...rHeads.php#241

FCar2000TA

iTrader: (7)

I did a bunch of research on heads over the past year. Basically, TEA and AI probably have the best heads, but also the most expensive. Texas Speed is probably the best bang for the buck. I decided to go with Frankenstein because their price is right in the middle, and flow numbers are close to AI and TEA, but with a smaller intake runner. I'm saving up now to get the Frankenstein work done to my 243's this spring.

Sladester2

iTrader: (1)

Thanks for the info guys. I have a NX kit I have waiting to put on but I wanted to try and hit 6s N/A honestly. I think for the cheap price of 243s I wouldn't waste the time porting my 853 heads. I just saw some 243s for sale on a Facebook group yesterday for $200 a set, guy had a few. Of course they were taken quick though but deals are out there.

2slowTA

2 tenths in the 1/4 mi is one thing but, 2 in the 1/8? Like said before, there might be a little more than 2.

Sladester2

iTrader: (1)

Yes 2 tenths in the 1/8th.. I am already so close cam only it would be a huge disappointment not to hit 6s if I added ported heads.

StealthFormula

iTrader: (35)

I agree. Quality ported 243s will allow that big cam to breathe much better plus would offer the ability to literally increase the compression ratio a full point or so between a thinner head gasket and a slight mill or just milling assuming adequate PTV. Going from factory 243s to ported 243s is one thing but going from factory 853s to ported 243s is another. I would absolutely do it.

Sladester2

iTrader: (1)

Thank you. Unfortunately milling is not an option with this cam. I also expected people to say huge gains upwards of 50 hp going from 853s but idk I suppose maybe not. I would be happy with 6.90s which I know is a big difference in the 1/8th mile but considering my first batch of mods dropped me 1.5 seconds I guess I'm kinda spoiled lol

MonmouthCtyLS7

iTrader: (6)

The shop I had my work done is a AI vendor, I was going to spend a little bit more on the 243's but they told me the 241 HCR heads are very close in numbers and these guys have done a ton of them. I would say stick w/ your stock heads, you might be surprised what you get out of them.

StealthFormula

iTrader: (35)

^^That may not be a bad idea now that we know the 243s wont be able to be milled given the PTV with the BTR stage 4 cam. Since milling the 243s is off the table, you're going to end up with about 10.5:1 compression with the 243s. If you go with the AI HCR ported 241 program it appears that you may be able to achieve 11:1 compression with your cam. If that's the case, that extra half point of compression will further soak up some of the hp/tq difference that you would see between the high compression ported 241 heads versus ported/non-milled 243s in your application. Of course this is all assuming that the high comp 241 program applies to the 853 heads as well which I do not know off hand.

ironmanLS1

iTrader: (9)

FWIW - In my last build, I ran a BTR stg 4 cam and 799's ported by TEA and milled .015". I don't recall what the PTV was other than the exhaust was greater than 0.090" and the intake even more. I sold the car and the combo has been running (and racing) for a couple years now. Ironically I am putting a different combo together over this winter, with a smaller cam and home ported 853's.