My 70 Chevelle and 75 Monte Carlo have 3-1/4 turns lock to lock. My 67 Impala had 4-1/2 turns L to L which was one finger steering and terrible road feel. Replaced it with a 3-1/4 L to L box, much better. 2-1/2 turns is probably too quick for a street car and better suited to Autocross.