Here's something I found on ls1tech.com
Quote:
Stock LS1 Flow #'s
Intake:
.100 67.1
.200 127.6
.300 181.3
.400 218.8
.500 236.4
.600 242.3
Exhaust:
.100 55.0
.200 99.6
.300 136.2
.400 157.6
.500 170.4
.600 178.1
Modified CNC LS1 TEA Stage I (stock valves) flow #'s
Intake
.100 65.1
.200 142.4
.300 206.6
.400 242.0
.500 257.3
.550 264.1
.600 269.6
Exhaust
.100 56.0
.200 111.9
.300 148.1
.400 178.0
.500 200.2
.550 210.0
.600 216.3
GM LS6/LS2
Lift Int Exh
.100 65 58
.200 138 113
.300 214 157
.400 261 191
.500 292 210
.525 295 212
.550 285 214
.600 282 218
|
The flow rates look very similar between the 243 heads and ported LS1 heads. Looks like a good used set of LS2 heads go for about 400-500 bucks. Also I believe the combustion chambers on the 243 heads are more efficient then the ls1 heads.