Interest in Custom built 4th gen V8 4.7 Doug Thorley Headers

[fo' runnin']

Not sure if anyone has answered this, but can these manifolds fit on the 03-04 even with the air injection pipe? Or does it get in the way for the non-vvti v8?

THIS ^^^ ??? I'd sure like to put these on my '03!

 

[montana_jeepn]

Yesterday morning I took my '05 V8 Sport with 70K to a local Toyo dealer for my timing belt maintenance replacement. I got the call later that afternoon that they installed a defective belt and have damaged a drivers side valve and will have my truck for maybe a week! I have the notorious 'manifold' leak and wondered whether I should have them replace the manifold with the DT headers while they have everything apart?? Any Input??

Do it, save some labor.

 

[csevel]

I guess they messed up four valves on the drivers side. Sadly they won't take apart the passenger side unless I'm willing to pay $1100 on top of the $750 for the headers...ugghhh I am having them install a OEM manifold for $600 for the drivers side..I sure hope it doesn't crack again within 20K miles!

 

[montana_jeepn]

It will cost approx $800 to install the headers at any shop. Just don't change your mind later and pay again.

 

[tollboothwilley]

I was at SEMA yesterday and ran into Dough Thorley headers. Saw these and had a lengthy discussion with Mike Johnson. They are working currently on the 03-04. I told him I would try to get a group buy set up possibly, if you guys want to do that. It would make it better for all involved. They are hoping to get them done within a week or 2.

I know there are a bunch of 03-04 looking for these. Mike told me that the 03-04 have a bolt in cat, so these would not be a weld-in setup. It would make this an easier install for those who are hesitant due to the welding that the 05-09 require.

Who would be interested in a group buy? We do not know final cost, but we can assume $650-700 is approximate for a group buy price. (Could possibly go a little lower, I'll work with him through my parts business to see about getting the best price)

 

[CruzadoBlanco]

I was at SEMA yesterday and ran into Dough Thorley headers. Saw these and had a lengthy discussion with Mike Johnson. They are working currently on the 03-04. I told him I would try to get a group buy set up possibly, if you guys want to do that. It would make it better for all involved. They are hoping to get them done within a week or 2.

I know there are a bunch of 03-04 looking for these. Mike told me that the 03-04 have a bolt in cat, so these would not be a weld-in setup. It would make this an easier install for those who are hesitant due to the welding that the 05-09 require.

Who would be interested in a group buy? We do not know final cost, but we can assume $650-700 is approximate for a group buy price. (Could possibly go a little lower, I'll work with him through my parts business to see about getting the best price)

ME! my POS pacesetter i put on already cracked so i need something better, and i love the bolton cat idea since i only have a mig welder to work with

 

[tollboothwilley]

Can I also make a HUGE suggestion to the rest of the group. The factory Y-pipe is the worst designed y-pipe i have seen. There are a few replacements. I just got a magnaflow replacement and I'll post up the differences hopefully later this week after SEMA is over... But I think this is one of the BIGGEST reasons for the failing headers. So much backpressure at the Y that the exhaust is seriously choked. Also, the factory manifold/header design is trying to force air to make a 90* bend, which causes so much turbulence. This is the reason these headers make extra gains. The ceramic coating helps hold heat in, keeping velocity high, and also helps prevent excessive engine bay temps. You really shouldn't have any concerns for losing the heat shields because of the coating.


2003-2004 V8 headers
1. Tollboothwilley
2. CruzadoBlanco
3.
4.
5.
6.
7.
8.
9.
10.

 

[the great him]

Oohhh ohhh me, pick me !!

 

[sr3tlaw]

I have a cracked manifold! Was on the fence on what to do. Sign me up Scotty.

Curious - is it bad for the car to drive with the manifold leak?

 

[Jagerzel]

I'm following and would like to know final price before committing - mines a 2003v8

 

[V8Man]

Can I also make a HUGE suggestion to the rest of the group. The factory Y-pipe is the worst designed y-pipe i have seen. There are a few replacements. I just got a magnaflow replacement and I'll post up the differences hopefully later this week after SEMA is over... But I think this is one of the BIGGEST reasons for the failing headers. So much backpressure at the Y that the exhaust is seriously choked. Also, the factory manifold/header design is trying to force air to make a 90* bend, which causes so much turbulence. This is the reason these headers make extra gains. The ceramic coating helps hold heat in, keeping velocity high, and also helps prevent excessive engine bay temps. You really shouldn't have any concerns for losing the heat shields because of the coating.


2003-2004 V8 headers
1. Tollboothwilley
2. CruzadoBlanco
3.
4.
5.
6.
7.
8.
9.
10.

Sign me up TBW for the 03 V8 headers!!

 

[jp8900]

Put me on the list.. Im interested.

 

[tony_4r]

Can we use the muffler/resonator of a Tundra 5.7 in our 4.7? I was driving next to one yesterday and i liked the sound. It sound throaty like a truck. I guess we can use an aftermarket muffler as well.
For those that have installed the DT headers, what mufflers did you install? Are there any exhaust sounds recorded somewhere?

 

[Bob J]

I was at SEMA yesterday and ran into Dough Thorley headers. Saw these and had a lengthy discussion with Mike Johnson. They are working currently on the 03-04. I told him I would try to get a group buy set up possibly, if you guys want to do that. It would make it better for all involved. They are hoping to get them done within a week or 2.

I know there are a bunch of 03-04 looking for these. Mike told me that the 03-04 have a bolt in cat, so these would not be a weld-in setup. It would make this an easier install for those who are hesitant due to the welding that the 05-09 require.

Who would be interested in a group buy? We do not know final cost, but we can assume $650-700 is approximate for a group buy price. (Could possibly go a little lower, I'll work with him through my parts business to see about getting the best price)

I'm interested.....:thumb3:

 

[V8Limited4wd]

Can I also make a HUGE suggestion to the rest of the group. The factory Y-pipe is the worst designed y-pipe i have seen. There are a few replacements. I just got a magnaflow replacement and I'll post up the differences hopefully later this week after SEMA is over... But I think this is one of the BIGGEST reasons for the failing headers. So much backpressure at the Y that the exhaust is seriously choked. Also, the factory manifold/header design is trying to force air to make a 90* bend, which causes so much turbulence. This is the reason these headers make extra gains. The ceramic coating helps hold heat in, keeping velocity high, and also helps prevent excessive engine bay temps. You really shouldn't have any concerns for losing the heat shields because of the coating.


2003-2004 V8 headers
1. Tollboothwilley
2. CruzadoBlanco
3. V8Limited4wd
4.
5.
6.
7.
8.
9.
10.

I'm interested!

 

[wmiranda]

Definitely Interested in a GB for these!

 

[07V8]

Are there dyno results? Does low end torque change?

 

[wracks03s]

x2! a set for mine and one set for the wife's.

 

[Angstrom]

My truck has been in the shop since last week getting the headers installed. They took them off last week, I had the cats welded on within a day but got back ordered on gaskets. Gaskets arrived on Saturday and I had all delivered for first thing Monday morning. The shops comments are that the headers are not mechanic friendly. Apparently getting the nuts back on are a real challenge as the tubes are in the way. Hopefully getting the truck back tomorrow for the weekend.

 

[BusinessHippieRH]

I'm interested in the 03-04 (as long as some kind of cat is retained)! But: it's going to be some time next year before I have the funds... moving is a b$%#h.