For the OP's situation, it appears that the overload current was not much in excess of the link's fusing current. With a slight overload, it will take a loooong time for any fuse to blow (a link OR a discrete fuse). It takes many minutes to blow with a slight overload and the wiring in the OP's case got hot enough to melt insulation, etc, beofre that fusing time was reached.
ANY fuse has a time versus current curve that depends on the design of the fuse. The key chracteristic is how long at what % of overcurrent it takes to burn out ANY fuse. Discrete fuses are NO different from fusible links in that regard.. .none, zip nada. So if you think a fuse will protect you better in the OP's situation, you are absolutely fooling yourself.
The only way to have a discrete fuse blow faster in a mild overcurrent condition is to use a fast blow type of fuse. But then you suffer from far more frequent 'nuisance' blowing of fuses caused by short transient overcurrent flows; these are common in automobiles with all the sudden changes in current and voltage with loads being switched on and off and so forth.
The fusible link is a good solution for automotive uses in the primary circuit feed line for this exact reason; it will blow immediately with a dead short but not suffer from 'nusisance blows' with transient load changes.
The problems with a single large fuse are:
1. The holder has to be high quality and most users don't get one. You just get an easier to change and resize fusing element but often at the cost of less reliable mechanical connections. You go from 2 connections to 6 when you go from a fusible link to a fuse holder with screw terminals.
2. And again, the typical large current fuse is a slow blow type, not a fast blow, so you are in no different position vs a link. If you can find a appropriate fast blow, you have to size it up even more to avoid nuisance blows, and you then again lose protection from slight overcurrent situation.
If you build a fusible link, you don't use just any wire. You use fusble link wire. It has a much finer stranding that resists annealing and breakage from vibration, and it has a high temp, thick insulation. The thicker insulation makes the thermal blowing characterictic more consistent.
- - - Updated - - -
Can't say the color exactly, but the '62 FSM for my Dodge B Body lists a 12 ga fusible link. Look for that characteristic more than color.
