NMAC BTWN GA ACFT AT SYR.

Narrative

I HAVE ABOUT 30 YRS OF EXPERIENCE; MOST OF THE LAST 20 YRS ON IFR FLT PLANS. ON OCT/XA/01 AT ABOUT XA00; I WAS SBOUND FROM WATERTOWN; NY; TO HILTON HEAD; SC; IN MY SENECA II AT 8000 FT ON AN IFR FLT PLAN. THE WX WAS CAVU AND I WAS JUST S OF SYR VOR WHEN SYR DEP TOLD ME TO TURN L FOR TFC. THEY NEVER TOLD ME THE LOCATION; DIRECTION OR ALT OF THE TFC; WHICH IS VERY UNUSUAL. I ASSUMED THE TFC WAS GOING TO PASS OFF MY R SIDE SINCE I HAD BEEN TURNED TO THE L. WITHIN ABOUT 30 SECONDS; A LIGHT TWIN PASSED FROM L TO R DIRECTLY IN FRONT OF ME AT THE SAME ALT AND SO CLOSE THAT I BOUNCED THROUGH HIS WAKE TURB. WE ALL KNOW THAT WINGTIP VORTICES BLOW DOWN AND DSND SO I WAS THAT CLOSE TO THIS ACFT. I WAS VISIBLY SHAKEN KNOWING THAT THE ACCIDENT WOULD HAVE BEEN FATAL FOR THE OCCUPANTS OF BOTH ACFT. EVEN THOUGH I MAINTAIN VIGILANCE IN THE COCKPIT; I WOULD NOT HAVE HAD ENOUGH TIME TO TAKE EVASIVE MANEUVERS; ESPECIALLY IN LIGHT OF THE FACT THAT I WAS SEARCHING THE SKY TO THE R OF CTR. A WRONG ASSUMPTION. NEGLECTING TO TELL ME THE LOCATION OF MY TFC COMPOUNDED THE PROB WHICH WAS DEVELOPING VERY QUICKLY. I FILED AN IFR FLT PLAN FOR ALL MY TRAVELS THINKING THAT 2 SETS OF EYES ARE BETTER THAN 1. IN THIS CASE; PARTIAL RELIANCE ON SYR DEP ALMOST COST ME MY LIFE. I FEEL THAT THERE WAS NO EXCUSE FOR THIS ERROR. GIVEN A CHOICE; I WOULD GLADLY HAVE DONE A 180 DEG TO NBOUND FOR A FEW MINS RATHER THAN RISK THIS ACCIDENT.