I have a Dynator copy of a Lucas C40T dynamo in my 289 Cobra, which works very well. As you can see in the photo, this car (a leafspring UK-market road car) has a cable tachometer drive off the back of the dynamo which this unit replicates. It all works beautifully with a very few wiring mods. I also have a dummy control box from Dynalite, which is very clever (just visible on the other side of the engine bay bulkhead). This has all the needed wiring modifications made internally, and incorporates a 40A (‘whole system,’ bar starter) fuse for added safety. Looking under bonnet, the only difference you can spot is that the yellow ignition light cable to the RB106 is connected to a different terminal from usual. The Cobra uses an ignition warning light and an ammeter, all of which I have retained for originality. Very pleased with it all round.
edit - sorry Wes, just noticed you are in the US. The main manufacturers of these in the UK are Dynator (as I used) and Dynalite (who supplied my RB106 control box). I could easily have used a Dynalite alternator as well. I don’t know who handles these in the US.