what is the inside diameter of the fuel hose that vents the top of the
gasoline tank--specifically the two about 2.5 inches of hose needed (on each side)
to hook up the overflow tanks in the fender well to the pipes that feed it. I
beleive the ID is 7mm but is it 8mm.

It's that fabric covered hose you've used on VWs for years. For the life of
me I can't recall the inner diameter. I'm actually looking for the
conversion--so what is the metric inner diameter and what will the standard equivalent be?

I'm replacing the the vent hose up top with High Pressure Fuel line even
though it only calls for the low pressure fuel line. The Low pressure line has
dried out and is leaking in this SoCal desert climate in three years time. So I'm
experimenting with the high pressure line to see if it will last longer in
this application. The high pressure line I can find here is only in Standard
measurement. The 1/4 ID has a 6.35mm ID. Can that work??

I'd just like to have the right hose before I pull the whole thing apart.
Thanks
Jeff
83.5 Westfalia
LA,CA