Which downpipe is best?

[qwks6]

I understood Terry Houston stopped making them when he went to jail years ago, so there are only the old used ones you can come across once in a while. No new ones. Correct me if I'm wrong.

 

[DJ Red Barron]

I understood Terry Houston stopped making them when he went to jail years ago, so there are only the old used ones you can come across once in a while. No new ones. Correct me if I'm wrong.

blackgn1 probably meant new old stock people have tucked away over the years.

 

[blackgn1]

Yep....new old stock stock. I'm installing this one soon. Brand new. You can find just about anything. Kinda like my virgin Stage Block!:biggrin: Buick guys always sit on some great parts.:biggrin::biggrin:

 

[qwks6]

Be careful with something someone sells you when they say it's a thdp. They haven't been made for years, but there are tons of cheap chinese rip offs being sold out there. Problem with them is they usually don't have good wastegate flapper assemblies. They are prone to sticking and causing overboosting. There is a terrible feeling seeing a boost gauge sweep up past your 22#'s of boost up to pegging it. Even for an instant.

***Safe thing to do is buy from a trusted vendor (like those on this site) that is making a similar product. They'll stand behind it. Never buy off e-bay.***

Simply from that flange you can see the difference between a real thdp and a copy, look at the bolt holes on the pics on this page and compare to the example above:

Downpipe Guide

I'd also whack that flange with a magnet to make sure it's stainless, if not they are prone to sticking pucks.

With all the money we invest in our engines I wouldn't chance my engine to a downpipe I am not sure will work.

 

[S2V6RACER]

Shane at Bigwood can make a nice custom downpipe too in 3" or 4", stainless or steel.