Debate, Headers, or Manifolds

[piecesparts]

The right design of header will enhance the scavenging capabilities of the exhaust system greatly. If you purchase a quality set, get them with a coating on them, and use teflon tape on the header bolts, they will install and last a long time. I have put headers on my 84 GMC, my son's 86 Chevy, my 2011 GMC, and also on my wife's 95 Impala SS, to top it off, I have a set sitting in my basement ready for my 68 Chevy LS engine. The change in performance was noticeable. However, if all you do is go to the malt shop on Saturday night with the little lady and then to the overlook behind the drive-in, for a few hours, then the stock manifolds are more than enough.

If you go to some of the perfromance websites and look at what many are doing with the different engines in many of the cars and trucks, the gains reported by dyno numbers are good with headers.

[K5owner]

I think the only real benefits of stock exhaust manifolds are: underhood noise is lessened, easier to work on or around(plugs, starter etc) tighter routing of exhaust pipes (lowered and 4x4 vehicles need it) and much less hassle come time to pass emissions tests.

Headers are best for horsepower, sound, torque and general performance.

[Tom]

Originally Posted by rich weyand

Simulator says you get about 3/4 of the gain of long-tube headers (over stock) when using shorties.

That simulator software isen't the most accurate thing out there. Shortys will give you the peak HP gain of long tubes most of time, but they can't match the low end power and torque of the longs. They do better then oem manifolds though for sure.

Originally Posted by Oregoon

What about some Ram's Head manifolds?

If you get the super rare 2.5" outlet manifolds sure, but then you run into clearence problems with the engine mounts. They were designed for older chassis's not the 73+. I ran 2" ramhorns on my 79 with a vortec 350 because I had them and I was broke after building the rest of the truck. I didn't like them, and they gave no more performance then standered log manifolds. They also just barely cleared the frame, 2.5" will not. They are ramhorn manifolds btw.

[KQQL IT]

I've had two pair of Thorley headers.
On two different trucks.
Good gaskets and arp bolts.
Zero maintenance since the initial retighten.
Zero plug or wire issues.
But as I said $600 as with anything you get what you pay for.

[Hubscrub]

Manifolds, reliable and mostly maintenance free most time they don't need gaskets even except the donut.

[Oregoon]

Originally Posted by Tom

If you get the super rare 2.5" outlet manifolds sure, but then you run into clearence problems with the engine mounts. They were designed for older chassis's not the 73+. I ran 2" ramhorns on my 79 with a vortec 350 because I had them and I was broke after building the rest of the truck. I didn't like them, and they gave no more performance then standered log manifolds. They also just barely cleared the frame, 2.5" will not. They are ramhorn manifolds btw.

Ramhorn... Doh! Sorry, long day.

The version my buddy used in his Impala sounds a lot nicer than the stockers he was running.

That said, sound and performance are very different aspects, very different goals, and not always congruent.

Also, I didn't consider the motor mounts... There's a lot of reasons I run inliners, and room is near the top of the list!

[scottybaccus]

Headers will move the torque curve upward, sometimes beyond what you normally use. Pay attention to the rpm range that you tend to hang out in, and look at dyno charts for the headers you might want. They should compare to stock manifolds. Instead of looking at peak gains, look at changes in the torque curve where you drive.

For me, daily drivers will get iron manifolds. Hotrods might get something else, but unless you are standing on the pedal through a full quarter mile, you may never experience the gains that headers offer.

[RDrancher]

I was checking out Tru-Rams from Speedway http://www.speedwaymotors.com/Tru-Ra...Iron,3823.html. With a 2.5" outlet, what changes in peak power range could one expect compared to stock (or 2" rams)? There is a review on that page for installation on an '82 C10 that mentions slight grinding on one of the motor mounts.

[mcmlxix]

Bringing this back up. Has anyone use 2.5" straight dump manifolds (Corvette Style)? I was looking at the Speedway Motors smoothie Rams Horns. Looking for any possible clearance issues.... I already have a mini starter.
http://www.speedwaymotors.com/Smooth...Raw,94194.html
http://www.speedwaymotors.com/Tight-...teel,1722.html