Headers Vs. Manifolds

[Thalidomide]

I have a 318 wth headers on it in my duster right now. I plan on swapping in a 360 sometime down the line. This is going to be a pretty solid engine putting out 350-400hp. This car is going to be dirven on the street and with headers the ground clearance isnt great. How much of a performance loss would I get if I swapped on some HP 340 manifolds? They offer much better clearance and they flow pretty decent too. My current headers are the hooker competition kind.

[Dart]

I wouldn't run the manifolds with anything but a stock engine. You would be basically putting a cork in the exhaust by using the 340 manifolds. I would think the whole performace package of the motor would be quite different and your top end would be terrible. The headers are worth 15-20 hp, besides the fact that they are good headers (Hooker Super Comp). I vote stick with the headers.

[PRO]

Im with dart on this one too,manifolds restricted even bone stock motors,usually you gain 20-25hp with a stock motor,just think what it does to a built motor..PRO..

[mtrv8n]

I have stock manifolds on my mp360/380, and I'll bet they're robbing a ton of power. However, the thing is so strong I don't notice that there is a lack. I don't race, but I hit 60 mph in less than 5 secs, and run out of road VERY fast. At 100mph, when I hit the gas she seems to jump. This in an e-body cuda. Of course, if you race and count tenths, or have been beaten by a Mustang, then go ahead and put headers on! Check out the post here about TTI, the ones to use if you are going that way.

[Dart]

I think you would pick up 25+ hp with headers on your combo. You say it runs hard now, but with headers you could really be flying...

[rumblefish360]

The Super comp headers have more clearance than the regular comp headers. There also more race than street. They would be better on a 400hp 360.

[Dart]

What is the primary tube diameter for the Hooker Super Comps?

[G Smart Dart]

Hey Thalidomide Just swapped out a 318 for a 360 and still have the 318 manifolds--They Suck--but for the last YR. or so I have been checking out headers. They almost all seem to hang too low--the exception I found were the TTI's. There 5 bills and lots of top end but I think the best way to go for the street is with the Spitfire Tri Y's. Lots of low end GRUNT and pretty good breathing overall plus all the room you want except for power stearing? You didn't say if you had it? I have a set on the way and will report the improvement---Spitfire Headers, Harold Johnson 3:30--10:00PM central time (501) 474-0120

[Thalidomide]

I have an automatic without power steering
Is there a website for the spitfire headers? or any pics?
This car is being set up for a fun cruiser/weekend road racer type of thing
nothing serious just fore a few kicks
the car is a little lower than stock an di have about 4 inches of clearence or less right now.
The super comps have better clearance you say?
I dont want to have to cut my fenderwells or anything.
Thanks for the replies.

[Dr. Righteous]

Remember if you add a cam, carb, intake, heads, you are still not PUMPING AIR efficently until you ditch the exhaust manifolds and go with a good set of headers.
Expecting to feel a difference on a stock engine isn't going to convince most people. They are noiser, they are harder to work around, they tend to get loose from the heads (cheap *thin flange*ones). Properly matched tube size *enables* your modification to perform to there max. They are a must for max potential in my opinion.

[440 Jim]

What kind of car and weight are you running? I had a '69 Barracuda with a 340 and the HP exhaust manifolds. The engine was bone stock except for the purple cam (old Direct Connection days). That car ran mid 13's in the 1/4 mile. For mid 12's I would say headers.

My current 440 E-body Barracuda runs 12.8 ET with HP exhaust manifolds, breather hot air from under the hood...