Rear end advice for racing with a 4 speed

MOPARMAGA said
Takes less power to run a Dana vs 9inch also

It depends on the ratio but yes, that is true. And the lower the gear ratio (higher numerically) the better the D60 is.

Gear selection is getting thin and that’s a shame because except for one small flaw it’s as good as the best 9 inch and far cheaper to build.