63 - Don't rely on the Google time. Most of the road isn't paved, and in sections the rocks are very sharp. I've seen lots of vehicles with flat tires including a Barcroft lab Taurus with two. I'd allow an hour from Grandview.
As for hiking time - that will depend. IIRC, it's about 7 miles to the summit over mostly moderate grades, or 14 miles overall. It's not a continuous ascent/decent - there are a couple of spots where you have to regain altitude. You won't think too much about them on the way up, but you sure will on the return! I've done it three times, and always waited for the gate to be open to so that I could park at Barcroft. That happens twice a year, and I don't have to fret about the marmots possibly chewing on my hoses and tires if parking at Barcroft. I don't know how realistic a concern that is, but I do know there are prodigious colonies of marmots living up there.
