I run my '46 with a '54 235 / 3:55 gears and 16x7.00 tires at about 60-62 on the highway. Engine now has over 80,000 on it since it was rebuilt in 1986. It'll go faster, but you can tell she don't like it. You can feel when you're pushing them too hard. Also, it almost goes without saying that regular maintenance is key, and not using motor oil made for modern car engines. Been using Valvoline oil for diesels forever and not a hint of smoking or oil burning (of course it leaks some, but that's a feature, not a bug).
