NMAC ON FINAL APCH TO AN ARPT IN CLASS B AIRSPACE (TCA).

Narrative

I WAS ON AND CLRED FOR ILS RWY 8R IN MVFR CONDITIONS. INBOUND FROM FAF/OM. RPTED INBOUND AS REQUESTED TO CTAF. APPROX 1 MI FROM OM MY PAX/PLT ALERTED TFC AT 11 O'CLOCK AND ABOVE ON COLLISION COURSE. I TOOK EVASIVE ACTION BY PWR BACK AND DIVE. THE OTHER ACFT PASSED OVERHEAD; MADE A 180 DEG AND NOTIFIED TWR HE HAD ME IN SIGHT. THE OTHER ACFT HAD BEEN CLRED BEHIND ME FOR STRAIGHT IN ON RWY 8R; BUT WAS HDG APPROX 210 DEGS (RWY 76 DEGS). CTLR SHOULD HAVE CAUSED SEPARATION TO OCCUR BY REQUESTING OTHER ACFT TO REMAIN OUTSIDE OF CLASS D AREA UNTIL I WAS IN SIGHT. I VISITED TWR AFTERWARDS AND CTLR RPTED TO ME AFTER OCCURRENCE THAT ACFT WAS INBOUND FROM FTZ VFR. CTLR STATED HE WAS OVERLOADED; VISIBILITY WAS BAD AND HE DID NOT HAVE TIME FOR RADAR ADVISORIES. THIS ARPT HAS BECOME EXTREMELY BUSY IN LAST 6 MONTHS DUE TO OTHER ARPT CLOSINGS. STUDENT CTLRS ARE IN CONSTANT USE; ALTHOUGH THIS WAS NOT A STUDENT CTLR. IT SOUNDS AS IF THIS CTLR WAS MANAGING BOTH RWYS 8R AND 8L AND HAD NUMEROUS STUDENTS IN PATTERN ON RWY 8L. CALL FOR MORE INFO IF REQUIRED.