I too have this....it did "get me out of a hole" and helped the van breathe much better and with a better throttle response, but it bloody rotted like an Alfasud.....I will replace with a stainless jobby when the 'purse keeper' allows.
The triangle (like mine) is the exit from the heat exchangers. There's two of them, the other is the Euro version. Two of the twin port jobbies. Look at yours. If it's the triangle version, I may be able to help, beyond that there are cheap ways and expensive ways, I've learnt both, let's talk when you're sure what you have.
merged 304 stainless here with a home brew return pipe in 316.... if you're running single/prog carb/heated manifold make sure whatever system you buy has proper provision to flow/return to collector
http://www.pdgough.com I will be taking him an old pair of oem heat exchangers keeping the original cores and having them re skinned in stainless. Pricey, but I wont ever buy any more.
Stainless original style one with JK stainless tailpipe. Still shiney 2 years later too unlike the rest of the van.
I have managed to track down a custom exhaust maker in Sweden and he sells off the shelf stainless systems thst look similiar to the original one,this is the type 4 motor im talking about. I sent him an email and he said he doesnt have any in stock at the moment but will have some ready in April,he has got me down for one! I will fit it and take pics etc and let you guys know how it is,if its all good I can get some sent to the UK. The price he told me would be just under 3000 sek. Not bad for a stainless system,he makes off the shelf systems for loads of other cars so i am guessing he knows what he is doing. I thread will be posted in April.