Top Speed - VIR vs Glen

Is the long back straight at VIR faster than the uphill back straight at the Glen?

I'm asking because I've never been in my current car - but will be there next week.

At the Glen I'm slightly exceeding my preferred rev limit but I do have a 4% higher gear if VIR is faster. I do remember the VIR back straight stays at top speed longer.

Thanks - Derek