Howdy Back Ralf and all:
Ahh! Yes, your stock carb will be a Carter YF, and it will be mated to a modern, vacuum and centrifugal advance ignition system. The YF is a good carb, and can be upgraded to a YF from a 1980ish Ford pickup with a 300 engine. IIRC the cfm goes from 185 to 210. It will be very stock in appearance and basically bolt on. Linkage, fuel lines, vacuum hoses and air cleaner should be a direct swap.
Please verify that your distributor is a point type???? You mentioned a Petronix upgrade. FYI- The first version of DuraSpark, pointless distributors began to appear in the '74 model year. The only way to know, for sure, is to take off the cap and look for the presence or lack of points. If you have points, then the Petronix is a good upgrade. If no points, open up the gaps to about .045" - .050" and enjoy.
The other option is a Carter RBS used on 250s from 1970 to about 1974. This is a different carb in appearance- very low profile and rated at 215 cfm.
Either of these carbs is a good performance upgrade, with a minimum of adaptation required.
Adios, David