Interest in Custom built 4th gen V8 4.7 Doug Thorley Headers
- Thread starter brighton
- Start date
Jason B
Official Vendor
Oh, just a reminder to anyone else with a 03-04 V8. The factory headers WILL FAIL eventually. Toyota's manifold design was very poor and the factory headers will end up cracking. They seems to last maybe 10 years before this happens. Also keep in mind that Toyota charges, $1,500 for factory headers! These are over half that, and have a lifetime warranty, add 30hp, 30 ft lbs of torque and better gas mileage!
Let's see them sexy goodness!!!
So sexy! How long did shipping take?
SilverAzRunner
New member
Mine came yesterday as well.
Very well packaged. Nice welds and the ceramic coating looks pretty even.
Waiting for time in the fab shop to get them put on.
Very well packaged. Nice welds and the ceramic coating looks pretty even.
Waiting for time in the fab shop to get them put on.
V8Limited4wd
New member
What are your plans for the installation? new cats and sensors? carryover the current parts?
isdriven
New member
Congrats to everyone who bought headers! I hope to do this sometime later this year. Can you guys post up what kind of prices you are seeing for install/fab work?
Question: So it looks like the 03-04 do not have the air injection system. Besides that, is there any other difference between the 03-04 and 05+ headers? I have bypassed my air injection system on my 05 and will not need it on the headers I buy. If the 03-04 bolt up to the 05+, that might be my best bet. Can someone confirm? Thanks!
Question: So it looks like the 03-04 do not have the air injection system. Besides that, is there any other difference between the 03-04 and 05+ headers? I have bypassed my air injection system on my 05 and will not need it on the headers I buy. If the 03-04 bolt up to the 05+, that might be my best bet. Can someone confirm? Thanks!
They bolt up the same, I was going to use Tundra headers and get rid of my air injection before doug thorley did the headers. There was a guy on Toyota120 that was making block off plates for the air holes but I didn't receive an answer from him a while back if he was still doing it. I don't know that it is required to block those holes. Something to look into.
Going to replace everything. Looking at flow master and the O2 sensors from URD. I just need to make a list of everything I need because I'm mechanically challenged and I want it done right the first time.
isdriven
New member
that's a good point, I didn't think if that, derrrrr:doh:. Maybe just get the 05+ headers and cut off the AI system and weld the holes shut.
You could make a little block off plate where the ai tube meets at the back of the header pretty easily. Weld or just use bolts to secure it. Same price for 03-04 and 05-09.
isdriven
New member
True, I was just thinking install would be easier of the AI runner wasn't there... more clearance to get to the studs. The AI bypass kit I bought came with block off plates. I have them laying around somewhere.
Nice. I've thought about doing the ai bypass. Can you pull the air pump out completely.True, I was just thinking install would be easier of the AI runner wasn't there... more clearance to get to the studs. The AI bypass kit I bought came with block off plates. I have them laying around somewhere.
isdriven
New member
I'm not sure but, my intuition says you should be able to. Although, I'm not sure if it would be worth the time and effort since you have to remove the intake manifold. I'm just leaving mine as they are.
Ya I was just thinking of getting any excess junk and weight out I could. Every pound out will offset heavy sliders and armor and such. Lol
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