Vacuum advance/retard can(for lack of better description) on my car which is a 70,1.7 with FI needs help, the retard side does not work. Can this be rebuilt? Do I have to replace it and if so do i need to find one compatible with the dizzy?

While I am asking questions had Petronix ignition installed would it be better to put in petronix coil?

Thanks

OK to be clear 1.7 is not my strongest knowledge area. I think the 1.7 only has an advance canister. The retard function is not really necessary except for meeting emission requirements. I am not sure they make the replacement cans anymore.

As mentioned the retard isn't required unless you have EPA smog testing,as long as your advance side is working you are fine.
ALWAYS match the right coil with Pertronix,the early ones will run with a Bosch blue coil or the one supplied by them,the Ignitor 2 has a lower resistance coil required and from memory can't be used with sold core wires to counter RF inteferance.
Buy The Ignitor 2 system and matching coil and do a full ignition service including nice leads like Clewitt Engineering or Magnacore as some have mentioned but I haven't used them.