conan

iTrader: (5)

Yes the 243 heads came on the Ls6 motors. GM made a lot of different castings of the LS head. The 799 heads are the new GM replacement for the 243's, if you can find some local to you. PRC uses a GM casting and then CNC ports the intake and exhaust runners as well as a valve job to increase the valve size. The big thing you want is to know what size combustion chamber of the heads your buying so you can then choose a piston to put your engine in the compression ratio you want. If your going to buy a set of used PRC or any used heads for that matter find out if the combustion chamber has been milled down to bump the compression on a N/A engine. You want the decks of the heads as thick as possible in a boosted application.

I would look around for these heads and see what you find. 243, 799, 317, or 241 would be my first choices if your staying with a GM head.

dklt1

thanks for the info I'm new to all this and all the information I get is very helpful! If I was going with the 243 or 799 heads what pistons would you recommend?

conan

iTrader: (5)

What is this car primarily going to be used for ? Track or street ?

What fuel are you going to run ?

dklt1

primarily the car will be used for the street hardly ever going to the track and if it does maybe once or twice a year, I plan to have the car tuned on 93 octane pump gas due to the lack of e85 where I live.

Detoxx03

iTrader: (14)

Save money from intake stuff and spend elsewhere.

conan

iTrader: (5)

Get whatever head your going to run and then pick out some pistons. Wiseco or Diamond are always a sure choice for brand. You can pick the dish once you know what CC combustion chamber the heads are. I would shoot for 10:1-10.5:1 compression range and run a LS9 head gasket. I would also recommend looking into a Meth injection kit as well.

Straker

iTrader: (1)

From reading a lot of posts I've seen this quote is the consensus when it comes to boosted motors and I'm searching for why that is but not finding anything. Now I'm not trying to be defiant, just genuinely curious, but in my case what would I be losing out on by throwing a blower on a forged 346 built for n/a? Is it just some max hp/tq? Efficiency? Reliability? Will it just run like total ****?

I spoke briefly to a tuner who does tons of boosted LS motors and he felt fine about installing the blower and meth kit, cranking the boost to 10-12 and figured ~650 hp would be no problem. I have no experience with blowers myself so just trying to figure the plan out. Very curious.

conan

iTrader: (5)

What specific question do you have ? Sure you can run a blower on a N/A forged 346ci and make good power.

01boydws6

iTrader: (19)

your setup that you are looking for is very close to mine
stock bottom end ls1
comp 224/224 cam
porter TEA 241 heads
stock ls6 intake
stock throttle body
F1a PROCHARGER
fmic
80#injectors
slp maf
twin 340 pumps
hooker blackheart 1-7/8" mid length headers and full blackheart exhaust

car made 614/540 on 10psi with the black heart setup
made 630/530 with a long tube header and home made true duals but ground clearance sucked (lowered on bmr springs)

my maf is maxed so im leaving some ponies on the table but for a street car it has great power everywhere and no loss in drive ability.

Bob's blower cam makes awesome power and he has always been very helpful when I had questions, he can get you hooked up with all the parts you need.

If you have questions or want to see video of the car just let me know.

ddnspider

iTrader: (26)

I wouldn't bother swapping heads for that power level and boost. Run a decent cam and itll make the number without heads. Valvesprings are a must but if youre doing a cam anyways then its not an issue.

Bob@BruteSpeed

iTrader: (16)

Thanks, I appreciate it! Bob