Scirocco Register

Sorry if this has already been answered but I have searched with no success.
What are the differences between the 1.6 exhaust to the 1.8.
I need vw196x back box and was wondering if any other scirocco/golf back box would fit

Thanks for any help in advance (last part to fit before respray)

What year is your car and what type?

Its a 1987 gt 1.6 carb

The early MK2's had a different back box, more rounded. I think a 1.8 back box will fit, I have fitted an injection back box to a carbed Scirocco in the past with no issues.