Doug Thorley Tri-Y Headers on 86 Chevrolet K30 4x4 454 T-400

[leadlobber7]

 Hi guys new to the forum here. I have a cracked exhaust manifold which gives me the perfect opportunity to replace my manifold with headers. Who doesn't want beautiful full length headers on their square body??  The first hurdle I came across was most header manufacturers that I looked into require you to move the cross member back 2 inches if your truck is equipped with a turbo 400 automatic transmission??  The next hurtle was trying to find an adapter to serfice this requirement, impossible as far as I found!!  So throughout my search I came acrossed some Doug Thorley Tri-Y headers that seem to look like they will work, does anyone have any experience or have they installed these on a similar application? Or definitely throw out suggestions keeping in mind that they must be ceramic coated and full length. Thanks guys!

[VileZambonie]

Personally not a fan of their headers and I think the visible welds make them quite ugly.

You won't gain or lose anything noticeable by running a shorter length header and if the only thing you can find causes a cascade of problems, then you have to ask yourself if you are achieving the desired end goal?

I run both full length and shorty's and prefer shorty's on my 4x4's now because of their ease of fitment, service and lack of exhaust leaks that occur. Is your truck stock, modified in anyway? If you are going to modify the outlet, what modifications are you making on the inlet if any?

In my opinion, the time to run full length headers is when it makes the most sense and your end goal is all out maximum performance. Running full length headers just because and not doing a complete performance build might just give you more headaches.

[ehjorten]

I had Doug Thorley Tri-Y headers on my 1991 V3500 with a 454, 4L80e, & NP205.  They fit perfectly and I had no modifications to crossmembers.  The RH side piping is tight running over the transfer case, but a good exhaust shop can bend the pipe to have adequate clearance.

[leadlobber7]

I had Doug Thorley Tri-Y headers on my 1991 V3500 with a 454, 4L80e, & NP205.  They fit perfectly and I had no modifications to crossmembers.  The RH side piping is tight running over the transfer case, but a good exhaust shop can bend the pipe to have adequate clearance.

Hey thanks man! I called Doug Thorley Headers last week and they told me the same thing. They told me that they design their headers around that particular  application rather than a wide range  of somewhat similar applications like some manufacturers do. This really helps so you don't have to deal with modifications. I felt really good after that conversation. What mufflers were you running? Thanks

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[ehjorten]

Running Magnaflows and 2.5" diameter pipe all the way to the back.  I have 3" exhaust all the way prior, but it was a little overkill for the TBI454 and I wanted to quiet it down a little.  It sounded great with the 454 and I hope it sounds just as great with the LQ4.