Distributor questions

Hey all, I have another question maybe someone could help me with . I replace the OE heads with Edelbrock aluminum performer heads and want to replace the distributor with a ready to run unit so I can get rid of the ballast resistor and voltage regulator on the firewall (I have already smoothed the firewall and painted the engine bay). I originally bought a pertronix plug and play but it hit the cylinder head so I returned it. I called MDS but the tech guy told me their ready to run unit was 4 3/4" which is even wider than the pertronix. I need to get a distributor which is approximatly 4" in diameter. Any ideas ? Like I said I would prefer a ready to run so I can lose the extra wiring and stuff on the firewall , although I suppose I could relocate these items to the inside so atleast they would be hidden. Thanks in advance for any help. Attachment 7669

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