Thread: big block head flow?

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Originally Posted by steelsixpack101

Of all you guys that have experience big block chevy heads(mainly oval port). Stock 781's oval ports usually flow 250-260 peak cfm intake and 175 peak cfm exhaust. I wanna know on average how much they flow when you do port matching, bowl work, and three angle seats and a back cut of the intake valves?

Is that with you porting them or a pro. cylinder head guy porting them?It might be eaiser if you give us some engine specs. and we can tell you if the are even worth using.

Originally Posted by erik erikson

Is that with you porting them or a pro. cylinder head guy porting them?It might be eaiser if you give us some engine specs. and we can tell you if the are even worth using.

My specs are 408 cubes, 4.155 bore, 3.76 stroke, 300in 310exh duration Mechanical cam with .556in 568exh lift. edelbrock rpm intake, 12.5:1 compression. hooker headers 2in or 1-7/8 diameter. L88 crank, stock truck rods with ARP bolts.

Originally Posted by steelsixpack101

My specs are 408 cubes, 4.155 bore, 3.76 stroke, 300in 310exh duration Mechanical cam with .556in 568exh lift. edelbrock rpm intake, 12.5:1 compression. hooker headers 2in or 1-7/8 diameter. L88 crank, stock truck rods with ARP bolts.

The 781's will work fine.
I would install a set of 2.19/1.88 do a good valve job,bowl blend, gasket match.Is this a street car or a drag car?If it is a drag car then I would look into a victor jr. intake.If it is a street car then your intake would work better because it will make torque at a lower rpm.