edwardvmassey
New member
Did you ever hear anything about this or get it done? I'm in Richmond looking for a place to install and the quotes are way high.
Interest in Custom built 4th gen V8 4.7 Doug Thorley Headers
- Thread starter brighton
- Start date
Did you ever hear anything about this or get it done? I'm in Richmond looking for a place to install and the quotes are way high.
groverdill
New member
Awesome Idea! Nicely done.
Jagerzel
New member
Thanks! They are longer than original due to longer cats but I'm sure the muffler place can hook it up.
SIDE NOTE :: Anyone replacing header bolts the correct socket is a star socket size E10. 8mm or 9/16 might feel like it's working but it ain't.
V8Limited4wd
New member
After dropping it off the $1k estimate went up to $3k so I ended up wasting my time with them.
Jagerzel
New member
For the exhaust manifold bolts that are stuck
Do not use this crap. It will just round the bolt out until it slips on itself.
Use this. Worked excellent, removed a stuck bolt that was only 1/2" sticking out and another bolt that was fully intact yet completely stuck (as noted in pic)
Do not use this crap. It will just round the bolt out until it slips on itself.
Use this. Worked excellent, removed a stuck bolt that was only 1/2" sticking out and another bolt that was fully intact yet completely stuck (as noted in pic)
Jagerzel
New member
Some D/T Header complaint
So after installing these myself I have a complaint that maybe future buyers can resolve with D/T. This is not to discourage purchase, and maybe I got misaligned headers or maybe I shouldn't buy first run anything but here it is. Bolt line up was spot on. O2 sensor line up not so much.
First up is the driver side header. The red arrow shows where the D/T sensor mount is. It is at the 3 o'clock position in relation to looking forward of vehicle. The sensor hits the heat shield that is mounted behind the header to the right of motor mount (not to be confused with manifold shield that needs to be removed). It would be a lot better if it was mounted where the green arrow is, at the 6 o'clock position where there is nothing below it and it would still reach the receptacle it goes to. So as you install sensor be careful you don't rub wires raw as you twist it in. You could remove the shield for just the o2 sensor install, but it still actually touches after complete install.
Second is the passenger side. Red arrow shows D/T position at the 11 o'clock position and green shows where it should of been, at the 6/7 o'clock position. White arrow shows where the receptacle is. The OEM position has the receptacle facing forward of vehicle. Due to the position of the D/T mount and height of sensor, the plug will not reach the receptacle. I had to unmount it, face it rear of the vehicle and zip tie it 2 inches higher to the same bracket away from manifold.
As these are minor problems none the less should be documented for future install questions and product development.
Other personal install note: Since my manifold heat shields broke off easily due to rust, I did not have to raise the engine to remove as mentioned in D/T instructions. Also my steering shaft would not disconnect due to being rust seized so I removed and installed headers without raising and lowering engine and not disconnecting the steering shaft. So with that said the passenger header went in no problem, with all 8 bolts installed. The driver side however I had to remove the lower right bolt (closest to cat converter) to get the header in due to steering shaft blocking me. Then after throwing a few nuts on to hold the header in place, install the last bolt, torque, then install nut.
So after installing these myself I have a complaint that maybe future buyers can resolve with D/T. This is not to discourage purchase, and maybe I got misaligned headers or maybe I shouldn't buy first run anything but here it is. Bolt line up was spot on. O2 sensor line up not so much.
First up is the driver side header. The red arrow shows where the D/T sensor mount is. It is at the 3 o'clock position in relation to looking forward of vehicle. The sensor hits the heat shield that is mounted behind the header to the right of motor mount (not to be confused with manifold shield that needs to be removed). It would be a lot better if it was mounted where the green arrow is, at the 6 o'clock position where there is nothing below it and it would still reach the receptacle it goes to. So as you install sensor be careful you don't rub wires raw as you twist it in. You could remove the shield for just the o2 sensor install, but it still actually touches after complete install.
Second is the passenger side. Red arrow shows D/T position at the 11 o'clock position and green shows where it should of been, at the 6/7 o'clock position. White arrow shows where the receptacle is. The OEM position has the receptacle facing forward of vehicle. Due to the position of the D/T mount and height of sensor, the plug will not reach the receptacle. I had to unmount it, face it rear of the vehicle and zip tie it 2 inches higher to the same bracket away from manifold.
As these are minor problems none the less should be documented for future install questions and product development.
Other personal install note: Since my manifold heat shields broke off easily due to rust, I did not have to raise the engine to remove as mentioned in D/T instructions. Also my steering shaft would not disconnect due to being rust seized so I removed and installed headers without raising and lowering engine and not disconnecting the steering shaft. So with that said the passenger header went in no problem, with all 8 bolts installed. The driver side however I had to remove the lower right bolt (closest to cat converter) to get the header in due to steering shaft blocking me. Then after throwing a few nuts on to hold the header in place, install the last bolt, torque, then install nut.
Propaganda
New member
How do these sound installed compared to stock? How difficult is the install, do I need to do some welding? Thanks, I have an 05 4runner btw.
Jagerzel
New member
It is difficult without proper tools for sure. Longer if you have to wait for tools to come in mail. You will need to weld the catalytic converters to the new headers at a minimum, and and the other side of cat either to a flange to connect to y pipe or weld directly to y pipe which I'm having a shop do tomm since I'm replacing the muffler too.
You need at a minimum:
-16 header bolts and 16 nuts (YMMV for replacing them)(all my nuts were rust welded to the bolts so all the bolts came out with nut except one I had to cut and one stuck bolt, both out with stud extractor)
-14mm 6pt ((((do not use a 12pt)))) socket that is not deep nor shallow, in between (got mine at lowes, impact type worked perfect, bolt studs all stick out past nut)
-E10 Star socket to install new bolts
-Stud extractor to remove old bolts
-14mm 12 point wrench for installing new nuts in very tight new header space
-UNIVERSAL joint sockets - this is a must. You can access all nuts with the right creativity to remove with these. Installing is all by wrench though.
-extensions and breaker bar for socket wrenches
-12mm and 10mm for various bolts to move stuff out of way like brake lines
-light to shine down through engine, flashlight, creeper, creeper stool
-welder or have it welded
-ford wrench or 22mm wrench for O2 sensors
-dremel with grind wheel to cut off rounded bolts (air power cutoff is too big)
-clear glasses for laying under the truck
-I removed both tires and the skid plates because you will drop crap and when you do you can't get it with the skid plates in so just take em off. Also you will be living in the front wheel wells so blow out dirt and grime.
-Heat shields, the instruction want you to raise engine to remove. Since they are trash with the manifolds, i was able to bend them back and forth until the broke, like you do with an aluminum can, and jimmy them out. You do not reuse them so thats that.
I'll edit if I remember anything and I'm sure others have more to add.
Last edited:
Jagerzel
New member
I would say no. The tower that holds the spring and shock is in the way. The steering shaft removed or disconnected yes will help.
Blackhatch
New member
So are the Thorley headers they only game in town for the 2003 V8?
Jason B
Official Vendor
It's a nice smooth sound, sometimes can make a catback exhaust quieter/smoother. Maybe some others can chime in. Now, if you remove every cat on the truck, not so,
For now it seems.
Doug Thorley 03-04 headers ORDER LINK
Doug Thorley 05-09 headers ORDER LINK
ALSO, I CAN THE MAGNAFLOW/FLOWMASTER CATS/MUFFLERS for anyone at great prices
Call/text me at 717-319-2100 to order over the phone, or to order online with a Credit Card, click below
HOJeepster
New member
It's a nice smooth sound, sometimes can make a catback exhaust quieter/smoother. Maybe some others can chime in. Now, if you remove every cat on the truck, not so,
For now it seems.
Doug Thorley 03-04 headers ORDER LINK
Doug Thorley 05-09 headers ORDER LINK
ALSO, I CAN THE MAGNAFLOW/FLOWMASTER CATS/MUFFLERS for anyone at great prices
Call/text me at 717-319-2100 to order over the phone, or to order online with a Credit Card, click below
Agreed, they don't increase the sound of the engine or exhaust much, if anything, it does 'smooth' it out a bit. I'm just glad the tick is gone.
I looked extensively and only found the DT's. It's a very tight fit but they work great. I felt a difference immediately and they sound great with the new cat back.
Yes and no. They are the only ready to go headers, but several used headers for a Tundra and were able to make them fit. Long or short tube headers.
Sent from the drivers seat of my 05 4runner.
Blackhatch
New member
Seems like those are hard to come by as well.
I saw the 1 thread. Is there any real cost savings in that option as of now though?
I saw the 1 thread. Is there any real cost savings in that option as of now though?
You can get them real cheap, but then you have to fiddle with them. Honestly, as big of a pita it is I'd just go with doug thorley. They are high quality and very well designed/built. I'm pleased with them and got a ton of horsepower out of them. Just know that whichever route you go it's expensive. They are extremely hard to get to and swap out.
Sent from the drivers seat of my 05 4runner.
Sent from the drivers seat of my 05 4runner.
Blackhatch
New member
Thanks for the follow up.
I am figuring on doing this on a lift and they do look like a PITB to get in there.
What exhaust did you marry them up to and did you ditch the cats altogether and go with the O2 sims?
I am figuring on doing this on a lift and they do look like a PITB to get in there.
What exhaust did you marry them up to and did you ditch the cats altogether and go with the O2 sims?
Yes, I ditched all 4 cats on mine. I have the universal URD O2 simulator but I have been so busy I haven't been able to hook it up yet. Hopefully in the next couple weeks.
For exhaust I had the shop install the headers, build me a dual 2.5"exhaust and I have a magnaflow race series muffler that is a dual in/dual out style. It's loud, not inside, just in general. I'm actually going to have a resonator put on each pipe just before the muffler to try and quiet it down for those highway driving moments I've been getting. Lol.
Sent from the drivers seat of my 05 4runner.
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