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How much does 243 heads flow?
The 243 heads as used on the LS2 motor flow at 260 CFM on the intake. LS6 243s (CNCed) with sodium filled valves flow a little better at 280 on the intake. The stock 241 head flows at 220 on the intake.
What are LS 243 heads?
GM 243 heads are General Motor’s 3rd generation cylinder heads designed for V8 trucks, SUVs, vans, and performance applications. The 243 heads are often called LS6 heads because they were found on the 2001 – 2006 LS6 engines. The 243 heads have a D-shaped exhaust and cathedral-shaped intake ports.
What is special about 243 heads?

What is special about 243 heads? The 243 heads deliver increased performance and extra boost – a flow boost of up to 32.2 cfm and 28.5 cfm on the intake and exhaust ports and a horsepower boost of up 20 hp. Its superior casting and better airflow, along with incredible design, make it a desirable choice.
Are GM 243 heads any good?
◼️ The 243 heads produce about 5% more power on flow alone. Although the 243s aren’t as reliable as the LQ5 or LQ9 heads (317s or 873s), it’s because the chamber is 71cc for the slight compression drop you want for forced induction.
Are 243 heads better than 706 heads?
Test after test has shown the 706 heads to have a more powerful output over the majority of the RPM curve when compared to stock 243 heads.

Are 243 heads better than 706?
While this may only be a few horsepower on the dyno, it can mean big changes for your engine at the track or on the road. Test after test has shown the 706 heads to have a more powerful output over the majority of the RPM curve when compared to stock 243 heads.
Are 799 heads the same as 243?
They’re the same…but in factory form the 243 came on LS6 motors with sodium filled vavles and better springs. early LS2’s had either 799’s or 243’s or a 799 on 1 side and a 243 on the other! I run 799’s on my car.
Are 706 heads better than 243 heads?
706 heads tend to be more popular than 243 heads with those who run naturally aspirated engines. While they don’t have the same size combustion chamber they also don’t have the tendency to lower the compression ratio and reduce horsepower.