Stock GM LS7 Heads:
Intake
302 CFM @ .400 lift
343 CFM @ .500 lift
360 CFM @ .600 lift
379 CFM @ .650 lift
? CFM @ .700 lift

Exhaust
200 CFM @ .400 lift
211 CFM @ .500 lift
220 CFM @ .600 lift
224 CFM @ .650 lift
? CFM @ .700 lift

MTI ported GM LS7 heads:
Intake
307 CFM @ .400 lift
351 CFM @ .500 lift
376 CFM @ .600 lift
382 CFM @ .650 lift
385 CFM @ .700 lift

Exhaust
203 CFM @ .400 lift
224 CFM @ .500 lift
233 CFM @ .600 lift
237 CFM @ .650 lift
240 CFM @ .700 lift

ETP LS7 41 Heads:
Intake
307 CFM - .400
340 CFM - .500
355 CFM - .550
365 CFM - .600
374 CFM - .650

Exhaust
199 CFM - .400
220 CFM - .500
224 CFM - .550
226 CFM - .600
229 CFM - .650