i had a 64 bell with a slant and 3 on tree. while i wouldn't say it was a world beater, it more than held its own for what it was. i could even one wheel peel it if i side stepped the clutch just right.
bought the car at the nats, drove it home with out a lick of trouble. drove it for about a year or so and yoinked the motor for a big block swap to sell the car. i had built up the rest of the car-- suspension, brakes, wheels/tires, interior in that time while leaving the six in there and it was a lovely car to drive that got a lot of attention.
that slant went into another car that had eaten up the #5 cylinder, coincidentally enough.