Why did you have to modify the firewall? Were you using the VNT-15 or something different? The reason I ask is because I'm doing the ALH swap into my 89 Golf and will be clocking the turbo up like yours was. I'll be using the stock turbo that comes with the engine (might update to the VNT-17 later).I'm hoping to not have to do that to mine if possible.
The pd 130 and 150 are the same except for ecu and turbo. I will might have to mount marks turbo upside down to clear the intake manifold. I am litereally int he middle of port matching and polishing the intake to the head, and the exhaust manifold as well. The actual port design on the 1.9 head is a lot better and the intake side is much larger. However the exhaust on the 1.9 almost seems smaller, by like a mm. But to match the exhaust maniold I'll be taking that much out anyways. The head will be going to the machine shop tomorrow to get the valve seats ground and a couple other goodies. Hopefully it wqill be back at the shop here by wednesday or so and than I can reassemble the head with the heavy duty valve springs and race ware headstuds and 1.9 metal head gasket. Than A custom grind cam ****** and I'll throw the pump on and all the other powdercoated goodies and it will be rockin. Especially witht he 4 puck cluytch and 6 pound flywheel!
As pictured, I was using the GT20 and ATP 8v turbo exhaust manifold, not the VNT-15. The VNT turbo will clear the firewall no problem, however you may have a problem with it interefering the rear engine mount. This was a problem on a B3 Passat I've seen, a MK2 I'm sure, and perhaps a MK3. It clears a MK1 no problem because it has a side engine mount rather than a rear mount. You can cut your rear motor mount to clear the VNT (and perhaps reweld it for strength) or just have a custom one made