THUMPIN455

Eh I dont know, I have headers on a 455 HO Formula, they are quite a bit rarer than a K code. It did come that way when I got it though. Its one of 276 built in 72, so sorta rare. Dont throw them away if you decide to put headers on, they are a good thing to keep. I have traded manifolds for entire cars before, they can be hard to find because junk yards pay by the pound and they are made of iron.

Headers make it louder, with a chambered exhaust it will be MUCH louder since they dont have mufflers that actually quiet things. You will pick up some power and they tend to make engines run a bit leaner due to increased scavenging. Im not a fan of flowmasters, they sound like a coffee can bolted in the pipes. How much power depends on what you put on there and what you take off. I havent seen any back to back comparisons with K code manifolds and different headers. I wouldnt mess with the cheap ones, I would go straight for ceramic coated super comps or something similar.

Starfury

Hipo manifolds are definitely better than non-hipo exhaust logs, but won't flow or scavenge as well as good tri-y's or full length headers. That said, I think you'd probably be happy with the factory manifolds unless you plan on spending a lot of time above 3k rpm. They're quieter and cooler under the hood and you won't have to tighten header bolts every other weekend.

Whatever you decide, do not throw away or sell the manifolds. If you ever sell the car, they should stay with it.

tx65coupe

I agree on keeping it stock if its a K code.

Like Starfury said, keep the HiPo manifolds if you do get headers. They should stay with the car.

2+2GT

Here are the manifolds. You got whichever manifolds depending on what engine you ordered. Which do you think will flow and sound better?

289 2v, 289 4v, 302 2v, 302 4v, including, weirdly, the 68 GT 350:



289 High Performance:



Here is the 289 HP with manifolds and the optional Arvinode exhaust:

http://www.youtube.com/watch?v=CnFXyLgcvLg

Houndstooth

They are supposed to scavenge better due to the 4 into 2 into 1 design. The cylinders are paired differently than a standard 4 into 1 design.

tx65coupe

http://www.barrett-jackson.com/appli...303&ln=65&it=1

indystang66

Thanks for all the replies! They are helping, I still have not made up my mind yet though. If I do go with headers I definetly plan on keeping the manifolds.

2+2GT

The Tri-Y design is a good compromise between manifolds and full-length headers. Full length actually loses power off-idle and low end, but shines at high end. Important for competition or driving at legal speeds above 90 mph.

Most Tri-Ys are a crap shoot on fit (as are full length headers) although I hear good things about these. Haven't used them personally, but their products are said to tuck up much better than most, and not bang against things. Only downside is they are made with collectors, instead of just welding the pipes together, so they are not "period correct".

indystang66

I do like those JBA Headers. They are pretty exspensive though arnt they? How important is it to go with ceramic coating vs. just stainless steel? I dont know if I can afford the ceramic at $899 vs $599..Worth $300?

Thanks

Starfury

Wow, $900? I'm pretty sure you can get a set of ceramic coated FPA's or Doug's headers for $700 or so, and they're both top notch.

Ceramic coating is the only thing that's really going to keep its finish. It also insulates much heat very well, keeping engine bay temps down and increasing the scavenging effect of the exhaust stream.