BURN'EM

iTrader: (11)

I just bought another Firebird tuesday. Its a 99 with a M6. I was looking around under the hood and seen it has 853 castings on the heads. My question is I have the 241's off my Trans Am would i benifit from having the 241's or the 853's ported up? My other option is to buy a set of 243's. I was just thinking since I have them what would be the difference in the 3? I'm sticking an F13 in it aswell when I start. thanks

SouthFL.02.SS

Send either the 241's or 853's to TEA for their Stage 1 program. Awesome mid lift flow numbers that rival stage II 243 heads. They peak around 295cfm at .550. I think it's less than aa grand if you provide the casting.

Or, 243 castings from PRC (at TSP) or Patriot 243's or Livernois 243's look great also, all checking in from $850 to $1150. These have great mid lift numbers, and carry past 300 cfm around .600.

BURN'EM

iTrader: (11)

isn't the chamber smaller on the 241 vs. the 853?

SouthFL.02.SS

Casting Number 853 or 241
LS1 (Center Bolt)
99-00 5.7L Passenger Car and Corvette (853)
01+ 5.7L Passenger Car and Corvette (241)
Material: Aluminum
Combustion Chamber Volume: 66.67cc
Intake Port Volume: 200cc
Exhaust Port Volume: 70cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches

Casting Number 243
LS6
01+ 5.7L Corvette
Material: Aluminum
Combustion Chamber Volume: 64.45cc
Intake Port Volume: 210cc
Exhaust Port Volume: 75cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches

Jason 98 TA

iTrader: (4)

You might checkout the info on our new outright PRC 243 LS6/LS2 heads! They sell for 849 a pair outright assembled & ready to bolt on! Sell your heads for $150 or so & your only out $700 doing ported heads!!

SouthFL.02.SS

^ You guys are making me wish I had money (and an ls1 vehicle) right now to buy those.

In a few months I'll be back in the game.

Gunnar@Patriot

iTrader: (20)

Here are some flow numbers on a set of our CNC ported 243 castings with stock valves. Heads were flowed on our Superflow 1020, 3.905" Bore, using a clay radius, and pipe. These are real flow numbers and you will recieve a spec sheet and a flow sheet specific to your set of heads.

.100" 75 / 62
.200" 154 / 121
.300" 215 / 165
.400" 254 / 200
.500" 285 / 217
.550" 292 / 221
.600" 301 / 226

We can do you a set of these bare for $845 or we can assemble them with 2.00"/1.55" OEM valves and LS6 springs for $865.00. If you use these heads, it will yield a 10.5-1 compression on a stock LS1 bottom end. We can also do any additional milling to these at no extra charge. If you have any questions, please let us know.

BURN'EM

iTrader: (11)

Thanks for the offers, but i think I will just have one of these I already have ported. I was just wondering of the 2 which would be better for the job?

SouthFL.02.SS

The 241's. Only because they're off your car already (assumption) and may be a bit better than the 853's with a similar port program. I'd make my decision with whichever head is easier to send them and bolt back on.

dudas35

iTrader: (4)

I have checked on the price of porting, it would be better to buy a set of already ported 243's instead of having yours ported. IMHO

JZ'sTA

iTrader: (23)

I agree for the most part.
Unless you have TEA run the program said above.
The LS6 option is a damn good one, and for as cheep as it is you cant go wrong.
Also the 241's and 853's are the exact same after porting.