Well, here's how I see this: Unless you're in love and have a spare $20k, you need to find a nice round-port and go for 52 - 55 MPH. Those logs are gonna limit your HP to about 425 - 450 net, so unless you're ready to put $4000 in a nice exhaust system your target is a bit high. Which is good, because even if you had the latest/biggest Crusader gearbox it's only rated for 450 lb/ft of torque and hasn't been made in 20 years. Plus, the Velvet Drive is rated to 500 lb/ft but only at 5000 RPM; they really don't like going much over 5200 without a costly build-up. And of course, these ratings are all with equipment in top shape. And this is where it all begins!
And have a Happy Father's Day (if it applies).