indystang66

66 hi-po 289

The manifold I have on now are pretty rusted.

So..Should I Get repro Manifold, Some Hooker Headers, or so repro headers.

Option 1: 65-67 MUSTANG HI-PO CAST IRON MANIFOLDS - PR. THIS QUALITY REPRODUCTION COMES WITH CORRECT OEM CASTING NUMBERS. ORIGINAL EQUIPMENT SET FEATURED ON COBRAS AND MUSTANGS WITH HI-PO "K" MOTOR

Option 2: Mustang Hedman Hedders
Increase performance and fuel mileage with a pair of Hedman Hedders.

Option 3: Newer high performance Flowmaster (or other brand)

Whats the difference In power and sound?

Also Exhaust: should get repro stock duals, or should I go with a flowmasters. Or stock with flowmaster muffler

Again difference in power/sound?

Option 1: 65-66 MUSTANG 2" DUAL EXHAUST KIT WITH FLOWMASTER MUFFLER. USE WITH ORIGINAL STYLE HANGERS.

Option 2: 65-66 MUSTANG ALUMINIZED EXHAUST KIT, 289 K CODE HI-PO DUAL 2".THIS KIT IS COMPLETE MINUS HANGERS AND CLAMPS. DESIGNED TO FIT AND FUNCTION JUST LIKE THE ORIGINALS AND INSTALL WITH ORIGINAL HANGERS AND CLAMPS.

Option 3: Newer high performance Flowmaster (or other brand)

Thanks for your time.

Starfury

Is this an actual K code car? If so, I'd stick with the manifolds you have. Just because they're rusty doesn't mean they can't be fixed up. If you pull them off and have them cleaned and bead blasted, they'll be as good as new. They'll also be quieter under the hood than a set of headers, and you won't have to deal with leaky header gaskets all the time.

As far as exhaust, unless it's a show car, I'd recommend 2-1/4" dual exhaust with your choice of mufflers. I hate Flowmaster 40's. They're obnoxiously loud, blatty, tend to drone, and they have terrible flow characteristics. I much prefer Magnaflow or Dynomax. I run Hushpower mufflers and absolutely love them, but they're quite a bit more expensive than most performance mufflers.

LynnBob Mustang

I'd go with a set of Tri -y's and a Shelby exhaust.

Lynn

indystang66

whats good about the tri-y's?

LynnBob Mustang

They flow good and I love the Shelby sound that goes with them. I have road in and drove several Shelby's when I was in my late teens and they sound better then anything any of these header makers make IMO.

Not too much to be obnoxious, but enough to let you know they are there when you open it up.

Lynn

rmodel65

well for one they are period correct and have great low and mid range torque which is what you need for coming out of the twisties etc....

but modern header tech far exceeds their design... i have tri-ys on my car though

indystang66

Thanks for all the help so far.

Can anyone tell me the differences between the original manifold and the tri-y's..

Power and sound differences??

Thanks

Starfury

Well, we've yet to establish if you have an actual K code car/motor. Answer depends on that.

indystang66

Yes, it is a K code. But Why does that matter? Didnt all the 289's come with manifold options anyways?

But yes its a K code.. So whats better the manifolds or headers? and what is the difference in power/sound?

rmodel65

if its a K code you want to keep it stock imho.....