Hello,
I would like to know if you have find a solution for the starvation problem. I've installed a Walbro fuel pump after I started using E85 on my 1.6 Golf. The car stopped just after enterring on the highway... So I'm planning to instal it like you but I wonder if it will work.
Moreover, my 1.6 uses less fuel than your GTIs, so I wonder if I should drill a smaller or a bigger whole.
Thank you.