To disc or not

[franken]

Best compromise is disk front drum rear.

BTW, the OP never bothered to mention what truck he/she has... A popular, swap is the whole front crossmember from a disk truck.

Heh, someone needs to go to Motortrend, Hotrod, or Carcraft web sites and see if they can find actual tests of late (front disk) vs X (front drum) year trucks, and say 2012 disk/disk and compare stopping distances.

Call them 1, 2, and 3.

A rule of thumb is 75% of braking effectiveness comes from the front. That is the fronts are much more important due to weight transfer.

1 is ok, but get them wet or hot and no brakes. Keep them adjusted.
2 is best compromise, but 25% effectiveness loss in wet or if they get hot.
3 Best.

Getting the drum brakes hot may be subjective considering shoe material.

The difference in drum vs disk is the leverage involved. you can apply more pressure squeezing than by pushing out. Similarly it's harder to compress a disk than it is to expand a drum open on one side.

Anyone who's driven a vehicle with only rear rear brakes will agree, they don't stop.
Similarly, w/o the rears, the brake system doesn't feel good at all...