For those people that want to have a steel conversion for their 1974-89 front fenders, TRE offers these steel boxes that can be welded to your existing fenders. After some small modifications (see pictures for where these need to be modified), the fit is good.
When backdating the 74-94 front fenders to the earlier 1969-73 style. Note the modifications that are needed for a better fit. The fenders' lower edge has to be cut, the new pieces overlapped, then fit to modify. Though we have communicated with the manufacturer about this problem, they will not make the needed mods in house for a easier installation. For the time being this is the best option out there. As you can see from the pictures the turn signal assemblies fit very well after the modifications to the steel units.
The pictures show how the lamps and grills would fit. Cost is for the metal boxes only. Lamps, lenses, and grills are all sold separately