'73 440 Cylinder Heads

[Charger Fan]

If you stick with the factory cast iron exhaust manifolds, other than a weight benefit, is there any performance benefit to be gained going with a set of better flowing aftermarket cylinder heads?

 

[pnora]

Of course there will be performance benefits.

 

[Charger Fan]

Can you explain?

 

[WileE]

Engine is an air pump. More air in + more air out = more power.

 

[OMTWF-72SE]

I did edelbrock rpm heads and think I got torque more than hp. There's a lot more grunt down low. But I'll admit that my car got a full rebuild after that which really woke it up. Its rarely at the top of its rpm range, I get my kicks from the rpms in the torque range. The best thing I did was make the move from tall gears to a 3.55. I love feeling the HD leaves squat and watching my 7ft hood rise.

 

[Charger Fan]

Engine is an air pump. More air in + more air out = more power.

I get it but doesn't that assume the stock cast iron exhaust manifolds are capable of increased flow handling the "More air in" by putting more out without creating higher back pressure correct?

 

[RemCharger]

I get it but doesn't that assume the stock cast iron exhaust manifolds are capable of increased flow handling the "More air in" by putting more out without creating higher back pressure correct?

Right and wrong. More air is going out, sure. But the doesn't mean it's not creating higher back pressure.
That's what headers are for.

 

[OMTWF-72SE]

Why would you spend money on alum heads and keep cast exhaust manifolds? Is this a looks thing or a money thing? I'd suggest the biggest air cleaner too with new heads. Can't flow more air with a tiny straw.

 

[WileE]

I get it but doesn't that assume the stock cast iron exhaust manifolds are capable of increased flow handling the "More air in" by putting more out without creating higher back pressure correct?

Best results are obtained by using a combination of modifications based on the end result desired.

 

[Cheapsunglasses]

Why would you spend money on alum heads and keep cast exhaust manifolds? Is this a looks thing or a money thing? I'd suggest the biggest air cleaner too with new heads. Can't flow more air with a tiny straw.

Money, 1 upgrade at a time

 

[OMTWF-72SE]

Ok, so depending on the cam you might have some flow issues if there's lots of overlap. And I'm assuming HP iron manifolds. TTI used to make a collector that bolted up to HP manifolds so exhaust could be better. There's a lot to consider.