Doug Thorley Tri-Y Headers

[56hotrodred]

So I am getting ready to order a bunch of parts before we head back up to Canada in March!

I am thinking on the Doug Thorley Tr-Y (Summit # THY-300Y-C) and was wondering if any body has any experience with them?

These will be going in my 80 1/2 ton frame and on a GM Ramjet 350 engine.

It looks like they do not include O2 sensors and I will have to cut a hole in the collectors!

I am also going to post on the square body forum.

Any thoughts?

[mr48chev]

Well 679 US $$ = how many Canadian $$$ All I am going to say is that the extra 500 bucks over what most headers cost must be worth a lot of bragging rights if you want to spend that kind of money on street headers. Your money if your pockets are deep but I' think that you can find a really nice set of headers for between 150 and 250 that will preform just as well even though they don't have quite the Bubba factor.

That said Doug Thorley headers have been around since I was in high school and always meant performance and were usually on race only rigs or serious high performance high dollar street rigs. If you have enough engine to justify them go for it.

[56hotrodred]

Thanks for your concern about how deep my pockets may or may not be and the current dollar exchange rate.

These are all things that I am very well aware of!!!

I have experience with other makes of headers, many in the price range that you mention, and in fact have a couple of them on other vehicles that I currently own! They have weathered and basically look very rough plus this is a truck that I have a long history with and plan on keeping for a very long time.

I do value other forum members input greatly and have utilized such to a high degree over and over again and will continue to do so.

Please do not take this the wrong way but I was looking for information on fit and customer satisfaction not on how expensive they are...thanks anyway!!!

[1project2many]

I have installed DT headers in other applications and they seem to be very high quality parts. This was late '90s so I do not know if anything is different today. There are cheap clones of some of their headers on Ebay and I wonder if this has affected DT pricing and quality.

[mr48chev]

I won't fault the quality. They have been around since the 50's and have always been known for building a quality product. It's primarily that I have always known their products aimed more towards racing than general street use but I see they sell a full spectrum of headers for street rigs .http://www.dougthorleyheaders.com/ You are correct in that I should not be concerned on what you spend on your truck. My bad for assuming that you were pipe dreaming a bit and looking at high performance pieces rather than street oriented pieces.
As far as fit, I don't think even the best fitting headers fit perfectly in every chassis they are supposed to be designed for. There almost always seems to be something that is there that wasn't in the original plans or on the chassis they used to mock up the header design. With those I would worry more about accessibility to the spark plugs and other things you need to get to. My experience with headers is that most manufactures think we all have skinny little hands an own a too box full of special spark plug wrenches.

I'd be contacting the manufacture directly and asking if they had any issues with installations in that chassis.

[56hotrodred]

I totally agree and have in fact an email into the manufacturer already.

[mr48chev]

Here is the instruction sheet http://www.dougthorleyheaders.com/im...00Y-C-INST.pdf

Their page on that part number http://www.dougthorleyheaders.com/19...-headers_15846

With them ceramic coated putting a bung in for the oxygen sensor is going to mess up the coating in that area.

Reading down through their warranty notes I found this and wonder how many guys have ruined a set of other brands of headers with header wrap that seems to be a favorite thing these days

2) The use of any type of “header wrapping” voids the warranty. Using any sort of wrapping
material on the headers destroys the tubing’s ability to dissipate heat, causing very rapid
deterioration of the metal and the subsequent failure of the headers.

[56hotrodred]

Hey thanks for including the instruction sheet. I have a very poor internet connection and had not done that yet.

One of the questions I asked the manufacturer was regarding the 02 sensor and its placement.

So far my research has indicated that people are putting it in the collector and not into the header itself.

Also so far I have not seen any headers that fit my chassis with an 02 bung hole pre-installed.

[mr48chev]

I poked around on there and didn't fin one. That would be the simple way to do it.
I'm going to be willing to bet ordered from Summit they will be shipped from the factory.

[56hotrodred]

Ya you would think that this day and age that they would be putting an 02 bung hole in at least a few of them!!!

I have done quit a bit of searching and have not found one.

It does however appear that putting the hole in the collector is working.

I do thank you for your efforts.

[1project2many]

O2 in the collector will work but I recommend making sure it's a heated type.