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Old 01-05-2013, 07:15 PM
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Fully port the intake and exhaust ports. Yes smooth and blend the short side radius.
Yes smooth and steamline the vavle guide boss to create two strong flow paths around the guide boss.
Do not fuss over wether the ports vary in flow by 1 or 2 cfm.
just make them visually as close as you can. The critical part that matters is the size of the push rod pinch area.
create a guage to check sizes.
Good result can be had with the stock valves. But on these head once fully ported a 2.02x 1.60 valve
or a 2.05x 1.60 valve set works very very well.
These headss need generous porting for good results. But use a felpro 1205 gasket as a guide.
Again do not fuss over minor variation in port flow.
This BS advice is from people who have never ported a cylinder head or actual built high performance engines.
How did we all create powerfull race engines before CNC porting and the internet?

These heads are capable of 260+cfm when fully ported with a 2.05" valve.
You can hit about 240cfm with a 1.94" valve.
which is a big gain from 198cfm stock.. 1-2-3 cfm don't mean squat.
Don;t be shy with the porting and do not listen to amateurs.
Racers have been sucessfully hand porting stock SBC cylinder heads
and getting big air flow and horsepower gains without CNC machines or flow benchs, since 1955.
I have been doing this for 35+ years. Long before CNC porting.
You can too.
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