Finally some Dany's Mag swap progress, and fuel line routing questions?

Bobzilla said
Have you tried duplicating this on the street?
Does your fuel tank have a vent?
I am still running stock 5/16” fuel line in stock six cylinder routing in my 75 Dart Sport. Not same body as yours, but supplies plenty of fuel to run mid 12 second passes with a 400 cube big block. I doubt your fuel line itself, size or routing, is the problem.
I had the same symptoms on two different GM F-body cars. Both were immediately, although temporarily, fixed by removing the fuel tank filler cap. Long term I had to add a vent.

I thought the same thing about the line size, but if we are redoing it, there is no kill like overkill, right?
Being a '66 it has a vented tank and not a vented cap. the vent is clear.
so far it can't be duplicated on the street, it really falls away at the top of 2nd and with trafic around here you can't stay in it long enough for it to nose over.