HP Manifolds or headers for 1974 Barracuda with 440?

[440_man]

My 440 Barracuda currently has 20+ year old headers on it that are rusted out and in need of replacement.  This car is just a cruiser - no racing going on - maybe an occasional power burnout to impress the youngsters. 

My dilemma is this - headers seem to always leak, have poor ground clearance, make starter replacement a misery, but have great power and sound.

Stock HP manifolds would solve all the problems, but how much power would I lose in a mildly upgraded street car?  The cam is a mopar purple shaft 240 duration at 0.050 with 284 lift if memory serves me right.  I have a 750 Barry Grant mechanical secondary carb, 2800 rpm stall, and 3.23:1 gears.  Car doesnt see over 5500 rpm.

If I made the switch to factory HP manifolds, would a cam change be advantageous?  Also what year HP manifold is advertised to flow the best?

thanks in advance for all your responses -

440_man

[440_man]

typo - .484 lift, NOT .284 lift....

[anlauto]

I remember years ago I went from headers to manifolds on my 440 Superbird I noticed a big difference in fun factor.. Only thing...expensive headers are worth the extra money compared to cheap headers...most of your issues would be solved with TTI headers.

[Chryco Psycho]

There are good reasons behind both choices , headers flow better & help the engine breath better , both TTI & Dougs make excellent headers .
Manifold can be ported to work better & have obvious advantages & disadvantages .
Cams with a 110 CL will work far better with headers as the scavenging effect is very helpful , with manifolds 112* CL works better as the scavenging is minimal , the factory cams has 114 -115* CL minimizing the overlap when both valves are open for example .

[mopar jack]

I ran that cam in my 71 barracuda with a stock 70 Chrysler 440 motor and stock manifolds. Raced the car in the street class on DOT street tires and averaged mid 13 second ET's. Changed manifolds to Headman headers and dropped .3 seconds off the ET.

[HP2]

Iron manifolds will have between .5 to .75 inch of the manifold face that contacts the head. This makes them seal against the heads very, very easily. By contrast, headers may have a little as .125 to .25 of facing material to seal against the head. That isn't much The position of the header flange relative to the bolt hole size and the holes location and the position of the gasket can have a huge impact on how well they seal.

In fact, I recently pulled the headers off an engine that had only run long enough to break in the cam. While it had no obvious exhaust leaks during the run in, it probably would have developed them if it was in a street car. The gaskets, which had notched end holes to allow them to be easy to slide down between the headers and heads, allowed the gaskets to drop down far enough that there was just a very thin, hair line evidence of a seal under the two front ports at the bottom and a correspondingly and similarly thin sealing imprint at the tops of the two rear ports. Obviously the weight of the headers resting on the bolts as they were being tightened down also contributed to this alignment. Each of these ports show carbon tracking that some exhaust pressure had escaped, but not in a large enough amount to start ticking yet.

Another factor that almost no one thinks of, I know I never did until recently, is how flat is that flange around the port on a set of headers. These flange are the weld beads around the ports where the tubes are attached to the flange. They are then blanchard ground to produce "identical" height on all ports. In inspection, however, I have found that this is not always the case and there are often high and low spots on these flanges that impact their ability to seal. A little bit of work with a flat file here can show the evidence of these difference and can help in making a more consistent seal on a port.

I've never looked at a set of TTi or Dougs. Perhaps they have wider and flatter port seals on their headers which is part of why their reputation for not leaking. If you need to replace your headers anyway, it might be worth looking into these. If you headers were in good shape but off, you certainly could perform welding and grinding to improve the port sealing surface around them without replacing them.  Its work that requires attention to detail, but it isn't hard, just time consuming. I've done this to every set of headers I've used for the last decade or so. I've even built up these surfaces to create different angles  where the headers meet the heads to eliminate clearance problems down by the collector.

[Filthy Filbert]

The proper gaskets are crucial to headers that don't leak. 

After trying many types, I've found a brand that WONT LEAK!!! Guaranteed!! 

Remflex is a thick compressible carbon graphite material that will mash and deform around any imperfections between the head and the header.  Or between the collector and exhaust pipe. 

Last motor I did, we didn't get 5 minutes into break in and the headers were leaking and sounding like a farm tractor.  We had used the exhaust gaskets that came in the gasket set.    Heads were new aluminum edelbrock heads, but the headers were a generic cheap old set of rusty heads that were on the car already.  Replaced the paper/foil gaskets with remflex and they sealed up perfectly. 

Their ONLY downside is that they are about 4x thicker than those thin paper/foil gaskets, so if you have tight header clearances, they may make it worse.

[RUNCHARGER]

Non stock engine in a later Cuda? Keep the headers, just anything but Hookers I think. Remflex gaskets are great I just put a set on my 18 Ram, I don't intend to change them later.

[7212Mopar]

I am running TTI header with aluminum heads. Gasket came with TTI headers, some type of composite and I costed both sides with copper spray. Stage 8 locking fasteners and no leaks in about two years.