[69gmcc10]

is this on your 71?

Drop spindles widen the track width if you are converting from drum to disc because stock height disc spindles are wider than drum spindles. You wont have a width difference with drop spindles if your vehicle already has discs. CPP sells 2 different spindles, standard width and "modular" spindles. Modulars narrow up the width of disc breaks for fatter tires so you dont rub the fenders.

Wider is better but I dont know if you will notice a big difference from that 1.5" of extra track width.

I would go with ECE and there McGaughys drop spindles.