Debate, Headers, or Manifolds

[Dannyboy1966]

I have a small block 350 in my 1986 GMC Sierra 1500. Which would you prefer? Headers? or Manifolds? and why you would choose them? Thanks for the input.

[LilD]

Manifolds. I don't think the tiny gain is worth the expense of headers.

[Tom]

Originally Posted by LilD

Manifolds. I don't think the tiny gain is worth the expense of headers.

That's a very one dimensional thought. Tiny gain on mustangs that come oem with short tube headers? Yup. Tiny gain on a 73-87 with any kind of mods done? Not at all. Even stock its a nice improvement percentage wise. Still not worth it to some, but to call the gains tiny is wrong.

[rich weyand]

Depends on what you want.

- Manifolds are cheaper, because they are the stock item, and you can get them used cheap.

- Manifolds are easier to hook the heat stove to for the thermostatic air cleaner.

- Manifolds won't rust out for the lifetime of the vehicle.

- Headers give a cooler sound.

- Headers give about a 20% increase in both torque and horsepower. In my setup, the engine output goes from 240 hp @ 4000 to 285 hp @ 4000, and torque goes from 355 lbft @ 2500 to 422 lbft @ 2500, or an increase of 19% in both. That's a big increase for a couple hundred bucks and not having to tear into things very far to do it.

[Gregski]

this ought to be a good one, let me pull up a chair

headers are better if you want braggin rights and have something to add to your forum signature (LOL) headers also may be lighter

manifolds are better in terms of fitment and replacement of gaskets with the engine in the car

[Gregski]

Originally Posted by rich weyand

- Headers give about a 20% increase in both torque and horsepower. In my setup, the engine output goes from 240 hp @ 4000 to 285 hp @ 4000, and torque goes from 355 lbft @ 2500 to 422 lbft @ 2500, or an increase of 19% in both.

Hi Rich, please don't take this the wrong way, but how are you coming up with those numbers? Are these numbers from an engine dyno or a car dyno (@ rear wheels)?

One would think that changing one component of the system such as exhaust would by itself yield no benefit unless the complementary input component such as carb or jetting or intake was changed / tuned / ported as well. Did you do any of those other things too?

[rich weyand]

Originally Posted by Gregski

Hi Rich, please don't take this the wrong way, but how are you coming up with those numbers? Are these numbers from an engine dyno or a car dyno (@ rear wheels)?

One would think that changing one component of the system such as exhaust would by itself yield no benefit unless the complementary input component such as carb or jetting or intake was changed / tuned / ported as well. Did you do any of those other things too?

Dyno simulator software. Just changing that one component. Breathing is very important, and you can obstruct it anywhere. Even in one component.

Simulation was done with generic 600 cfm carb, but with a dual-plane (i.e. not stock) manifold.

[KQQL IT]

If you want painless headers.
Plan in spending $5-600

[motornut]

running a Stock block?,and drive during the winter,less maintenance.
you can clean manifolds up and get a little more noise/flow out of them.
just clearing up the insides can make a difference,
getting rid of the noise disturbing bumps in the stock manifolds.

[K5owner]

It was actually cheaper to go with the edelbrock t.e.s. emission legal headers then to replace the cracked manifolds in my k10. Being California I have to have all the smog tubes and thermostatic housing to pass the visual test. The passenger side manifold new with the stove pipe was 300 bucks alone. I couldn't find it used in 2009 when I needed it. The driverside I had no problem finding. But that still ran 125 new. The yes headers cost $399 and were shorties but coated. I will say spark plug changes are much easier with manifolds as getting to them with the headers is a pain.

[RDrancher]

Good questions, and one I've been asking myself as well.

I have an '85 Suburban with stock manifolds right now. I removed all of the smog fittings and plugged them with cummins drain plugs. I've already purchased an aluminum intake and Summit (Holley) 600cfm carb. I'll be going to 2.25" dual exhaust and am now deciding on whether to go with stock manifolds, shorties or full length headers. I'm not sure about the full length since I'll be lowering the front suspension. Are shorties worth it?

[rich weyand]

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

[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.

[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!

[Oregoon]

What about some Ram's Head manifolds?

I imagine they'd fit in a truck fine, and they're reputed to be the best of both worlds: Better flow, cast iron.

I have no experience with them personally beyond what friends have done, but they come highly recommended.

Speedway has a pretty nice looking pair, and I think they're the same one's my buddy put in his Impala.

[pontiac6269]

I have LT1 exhaust manifolds out of a 96 Caprice on my 81 C20.

[donut]

What ever's the easiest for you. My plow truck had headers, as it was 40 miles to an exhaust shop that could bend the pipe. Summit exhaust kit made it legal to drive.

Current truck has headers as it was much cheaper and less of a pain to repair all the exhaust leaks. Smog tubes were also seized in the manifold, soooo sawzall time.
This one's also a 454, so smog tubes were pretty good size and extended into the exhaust port of the head. Capping wouldn't have fixed that.

I did try to keep the manifolds on both trucks, though it would have been a bunch more work.

[motornut]

I grind them smoother

[aotte1]

Just my option!!

Depends on how you use your truck? Daily driver manifolds, more of a fun truck then consider headers( but like Cool-it said quality headers cost money, cheap ones often take a lot of maintenance )


How much money do you want to spend?

Fitment and ground clearance issue to consider with headers.

Headers often are louder! Can be annoying on longer trips.

If going with manifold, I alway have used ones milled flat on the head surface. Other wise you can have exhaust leak issues.

Hope this helps you make your decision. Headers have their place, however, manifold are simpler, and.......

Les

[OlRed87v30]

Manifolds will last longer with less headaches and headers are ideal on high HP motors where every ounce of air coming in is matched with an exhaust system that blows it out. Not saying you may not have any gains but not worth the peeformance vs price and satisfaction. If me, KISS method; keep it simple stupid.

[K5owner]

One thing I can say about at least my headers were that they were difficult to seal at the collector. I went through several different applications of gaskets until I found one that worked. Edelbrock doesn't sell the gaskets by themselves.

[Dannyboy1966]

Thanks guy's, I really appreciate your input on this subject. I've got headers on it right now, and it is a daily driver, so like a couple of you have said they can be a bit on the noisy side. Since I'm running a SM465 with 373 rear, anything I can use to tone the noise down in the neighborhood at 4am in the morning might make my neighbors a little more happy.. LOL So it's off to pick n pull to find me a set of manifolds on the first warm day i get.

[SkinnyG]

I have been VERY happy with these header and collector gaskets: http://catalog.remflex.com/

[Sodak]

I do know one thing.. and it's on this truck i just baught.. it has headers put on from the previuos owner.. and that i had to change a starter on it and the only way to get it out was to take the bump stop off on the passenger side..now with manifolds never had that probem.. would i change them out..nope sounds too nice.

[cadillac_al]

My truck had headers on it when I bought it and I am too lazy to change them. It has quiet mufflers though and nobody knows the headers are on there. When my exhaust rusts off and IF I have a good set of manifolds around I would probably run manifolds.