Different between hp manifolds and logs

[Fern]

Do the hp manifolds flow much better than the standard iron logs?
I don't like headers and was wondering if the hp ones are much better than the logs?

[CUDA JAS]

Small block / big block???

Any details on the engine?

Jason

[Fern]

It's a 440 with rpm intake and 770 carb.
Will the exhaust flow much better with hp manifolds or not really Andy gain?

[Fern]

I have late model mopar exhaust manifolds now, will switching to 70 style hp make a lot of difference in flow

[1 Wild R/T]

Plenty of big blocks running HP manifolds make 500+ HP, yes headers will make more.. But come with their own problems.. Do you need every late bit of power or do you want a better street driven experience....

[Fern]

Are all 440 manifolds the same regardless of year?
Are they all high performance?
Or are some better than others?

[rUNCHARGER]

Lots of differences in 440 manifolds. A-body, B/E body and C-body are generally different in fitment as well as outlet size and clocking. There would be some benefit of HP manifolds over logs but I don't think anyone has ever tested them except for Chrysler engineers. Back when this stuff was in the junkyards 383-2 B and E bodies netted me lots of HP manifolds to bolt onto the 440 engines I pulled out of C-bodies.

Sheldon

[Fern]

I have (I think) manifolds from 1977.
Would anyone think 1970 hp manifolds would be a big difference?

[turbostang7]

Unless you are getting the HP manifolds for cheap or free I wouldn't worry about it (if you are looking for the "look" that's another story)
the HP increase on a stock 440 is probably pretty negligible and only noticed on the actual dyno not the butt dyno. 

[Chryco Psycho]

The specific casting will not make a huge difference as long as they are the high rise HP maniolds , I also port as much as I can reach , make sure the port window at the head is bigger than the head & not overhanging the port