Headers,,,,again?

[big66440]

I have a 66 D100 SWB, 318 LA soon to have an A518 OD and was wondering if anyone can help me find a good set of headers (tri y's preferably) that will fit,I know about the hedmans 79010 and thats probably the route I'll go if I don't find what I'm looking for,I was wondering if the doug thorleys part number TH146Y would fit but theyre advertised for 72 and up motorhome,I read a post on here abut a guy with a small block that installed doug thorley's on his but I dont know what year his truck was,What years are sweptlines or Dodge trucks mostly the same as far as headers go? sorry if this topic has been discussed before,I just want to straighten everything out once and for all,thank you.

[soopernaut]

Anything pre-69 has that crossmember that seems to get in the way. Some have solved this problem with creative routing. There was a 71 that I encountered that the owner used 72-93 headers and had no fitment problems. It might not be as simple on a 66.

[Hobcobble]

Sweptline [100/200] frames were the same from '61-'68
and then changed for '69-'71. The earlier frames have
the bell housing cross member [or the stub ends if cut
for an auto tranny] that narrows the choice of headers.
John

[Rodger]

Enrique

Since you are learning from more than one source that installing
after market header's is not as easy as the ones who have them
are claiming and the header's start working at about 3,000 RPM's
which puts you in the Radar Gun of the CHP, why not use a proven
Power Enhancement for your exhaust.

Rodger & Gabby
COS

[big66440]

oh you caught me !!!,,, LOL!

[Stinky]

Hobcobble's right. I've got a 440, and if it wasn't for the automatic, with the old crossmember cut out, my heddman long tubes wouldn't fit. I've got an awkward bend right after the connection from the pipe to the header that makes everything work.

[RH62]

Enrique

Since you are learning from more than one source that installing
after market header's is not as easy as the ones who have them
are claiming and the header's start working at about 3,000 RPM's
which puts you in the Radar Gun of the CHP, why not use a proven
Power Enhancement for your exhaust.

Rodger & Gabby
COS

Roger
Is that the muffler you have? If so how does it sound? What inlet/outlet sizes does it have?

[nfury8]

A stock 318 isn't going to gain much from headers and the OD is going to keep your RPMs low on the road.
With that said, I have a similar setup with headers, although the 318 is a EFI Magnum. I used the Magnum
shorty headers, which are designed as a direct replacement for the Magnum logs. They will breath a little
better and because they rear dump up high, might help you avoid cross member issues. I picked mine
up cheap and used on Craigslist. They are Pacesetters.




Summit makes their own version, which is a steal at $155!
http://www.summitracing.com/parts/SUM-G9044/

[Rodger]

Scott

The NAPA # 22599 Muffler is the same dual inside diameter as the exhaust
manifolds in any 273-318-360 engine. They also match the V10's that Dodge
uses.

Yes I use the same muffler. The muffler sounds much as a stock exhaust
system sounds on the truck. What I like is the performance record. The
performance is the "seller" to me since this is the performance of dual
exhaust and the cost of a single exhaust system.

This muffler would be a match for the headers shown.

Rodger & Gabby
COS

[big66440]

Thanks alot for all the input,think headers are toooo much of a hassle with the heat and the leaks and all,any suggestions for manifolds asside from the million dollar hi po 340 ones?

[RH62]

Scott

The NAPA # 22599 Muffler is the same dual inside diameter as the exhaust
manifolds in any 273-318-360 engine. They also match the V10's that Dodge
uses.

Yes I use the same muffler. The muffler sounds much as a stock exhaust
system sounds on the truck. What I like is the performance record. The
performance is the "seller" to me since this is the performance of dual
exhaust and the cost of a single exhaust system.

This muffler would be a match for the headers shown.

Rodger & Gabby
COS

Roger
Ive been trying to find more info on the muffler you are talking about.
I found this one but it says its a resonator....
is this the one and if so whats the difference between a muffler and a resonator?
I thought a resonator was to be run in addition to a muffler on newer cars.
thanks
Rich

http://www.dmauto.com/web/dmauto/Catalo ... EXH/22599/

[Rodger]

Rich

I got my # 22599 Dual two inch In-let Muffler from NAPA ( as I have
babbled about ). They had it on the shelf and it took longer to look
at the books than to walk back to get it. It does appear much as
what you are showing.

The plain brown card-board box said NAPA on it.

The owner of a local muffler shop informed me of the dual exhaust
actions and the cost of a single exhaust system. I had already
known about the 1966 Dodge Truck's using a like system, but
did not think to highly of it due to my lack of knowledge at the
time.

Once I sharped my pencil and moved from the back of the class, I
felt as if I had learned a secret.

Rodger & Gabby
COS

[Rodger]

Hola All

Here is a photo that I took of a 1970 LA-318 powered truck that had
the first series Magnum Exhaust Manifolds on it. The clearance at the
driver's Exhaust Manifold exit tip was tight, but it cleared.

This truck has the NP 435 Manual Transmission.

Rodger & Gabby
COS

[shdnobetter]

I'm running the Thorley TH146Y's on my '71 with a 360. I had to offset the centerline of the headpipes down about 3" from the centerline of the collectors to clear the trans. xmember and relieve the xmember slightly on the pass. side, but since I was building the system from scratch it was no big deal.

[MountainMoparRobin]

Lets get the information correct, headers start working from the moment you start your engine, their isn't a manifold built to this day that can flow better or match the torque numbers of long tube headers even at idle, long tube header would give you more torque at idle than any stock manifold, hands down regardless of RPM"S and if you put studs in your heads in replacement of bolts you'll get rid of leaks, the only time you run into problems with headers is when you have a cheap set on a 440 where the plugs are sittin right on the exhaust. your torque numbers are more than 10% higher at idle with headers

[Rodger]

Robin

Please post the graph of at least three improvement's of some
results of an improvement from idle to 3,000 RPM's that
are for any 225, 318, 360, 383, 400, 413, 426 or 440 engine.

If you do have this said information, only do it if the parts
are availible.

No graph = no post
words only = no post
no part number or new part = no post

Rodger & Gabby
COS

[shdnobetter]

Lets get the information correct, headers start working from the moment you start your engine, their isn't a manifold built to this day that can flow better or match the torque numbers of long tube headers even at idle, long tube header would give you more torque at idle than any stock manifold, hands down regardless of RPM"S and if you put studs in your heads in replacement of bolts you'll get rid of leaks, the only time you run into problems with headers is when you have a cheap set on a 440 where the plugs are sittin right on the exhaust. your torque numbers are more than 10% higher at idle with headers

Actually, Robin, the advantages of headers come into play at the point of throttle opening and rpm (load) where the stock manifolds begin to exhibit their inherent pressure drop (or restriction, if preferred). This is almost certainly going to be above idle. There's another advantage that cast manifolds have over most headers, and that's thermal efficiency; more latent heat is lost through the steel header tubes than the thick cast iron manifolds, though having the former coated helps.
I think both systems have their merits, and I also believe you get what you pay for, at least as far as headers are concerned. If I hadn't come across the deal I got on the Tri-Y's, I would've installed the Magnum manifolds without any reservations.

[surfnuke9]

some good engineering info here....

http://victorylibrary.com/mopar/header-tech-c.htm

here is a graph showing what headers did over stock manifolds an a small block Chevy.

And dont get all "MOPAR only" on me, fluid flow is fluid flow. There isnt that much difference between a small blocks airflow and manifold design from any of the big three.

[MountainMoparRobin]

Roger,
since the beginning of engines the first improvement always recomended is Headers! thats the cheapest and quickest change that has been around since the 50's, to get more horsepower and torque. that hasn't all of a sudden changed in the last 6 months. Now whether or not a person chooses that route is total personal choice, and headers aren't needed for every situation, and their is no way you can possibly try to tell someone that both manifolds going into 1 muffler and 1 exhaust pipe is a good flowing system over a dual system thats basic exhaust history back pressure. now granted not everyone wants or needs dual exhaust. Manifolds are fine and nothing wrong with them, but they have never outflowed headers.

[Rodger]

Robin

I see that you have not read the post. Here it is again so that
you understand what my subject matter is .

" ... Please post the graph of at least three improvement's of some
results of an improvement from idle to 3,000 RPM's that
are for any 225, 318, 360, 383, 400, 413, 426 or 440 engine.

If you do have this said information, only do it if the parts
are availible.

No graph = no post
words only = no post
no part number or new part = no post ..."
=============================================================
The graph on a chevy is great, but if one can not find
or know about the MoPar Parts to equal the chevy parts,
then where are we .

Again,.most driving is done with engine speeds from an idle to
3,000 RPM's so test and build where for you drive at. This is why
I have said the under 3,000 RPM part.

Rodger & Gabby
COS