Hi, ive a mk4 astra van. 1.7cdti. And i want to fit an aftermarket backbox i have spare. I can weld, and have access to a pipe bender.
I need to know what the inlet bore of the std backbox/external diameter of the centre section (its an 05 plate, so centre section to backbox is sleve fitting)
So i can get some corect diameter pipe, to bend to shape and weld to the backbox, meaning it slips over the centre section and is clamped in place.