Rear end advice for racing with a 4 speed

8 3/4 backbrace installed... $200?
Good 30 spline axles... $3-500.
Detroit locker (assuming you don't want a spool on the street, or having to repair suregrips repeatedly) $900.
Total $1500-1700.
Dana 60 from strange... $2500-$3000. Minus sale of 8 3/4 $500
With SLICKS and a four speed, a Dana or 9" swap is a no-brainer.