Afraid I can't help too much on the T Bird, but I have some thoughts on your "C".

If your looking for an upgraded iginition why not go electronic?

I had a customer with a 300F that converted his stock distributor to electronic many years back and I am doing the same on a couple of Hemi projects I am building.

The conversion is pretty straight foward.

Remove the vacume advance, breaker plate.

Remove the top of the distributor shaft (the point cam and advance weight assembly). It's held on with a small clip located in the center of the shaft located under the rotor, there may be a small piece of felt covering it.

Install a small block (mid 70's) reluctor/advance assembly, breaker plate, pickup and vacume advance. Don't use big block items as the vacume advance works in the opposite direction).

It will use the stock cap and later style rotor.

All thats left to do is wire in the later control box and it's ready to go.

The setup uses the later rotor and stock cap.

As you retain the stock housing and shaft you also still have the tach drive.