GA SMA HAD CLOSE ENCOUNTER WITH UNKNOWN ACFT THAT WAS IFR AT 7000'.

Narrative

WE HAD DEPARTED ROC AND PICKED UP A SQUAWK CODE FROM BINGHAMTON WHICH WAS PASSED TO ZNY AND THEN TO ZBW; THEN BACK TO ZNY. BEFORE LNDG WE FLEW V34 DIRECT TO HNK; THEN LORAN DIRECT TO DXR. THIS PUT US ON V167. VERY CLOSE TO HELON INTXN WE HAD A CLOSE HEAD ON ENCOUNTER. EVASIVE ACTION WAS TAKEN BY BOTH ACFT WHILE UNDER ZBW RADAR. THE OTHER ACFT WAS IFR IN VFR CONDITIONS. I ASKED CENTER WHAT STEWART'S ALTIMETER WAS AND CHKED THAT MINE WAS SET PROPERLY. IT WAS AND I WAS WITHIN 75' OF MY ALT OF 7500' MSL. THE OTHER PLT IMMEDIATELY STATED I WAS NOT AT 7500'; BUT CLOSER TO HIS ASSIGNED ALT OF 7000'. HE THEN CALLED CENTER TWICE; QUESTIONING WHY CENTER HAD NOT CALLED THE TFC. FINALLY CENTER STATED HE WAS SORRY FOR NOT DOING IT. THE OTHER PLT (TYPE AND N NUMBER UNKNOWN) WAS MORE VERBAL AND UPSET ON THE RADIO. CENTER WAS NOT REAL BUSY AT THIS TIME; IN MY OPINION. I SLEPT ON THIS OVERNIGHT AND THEN CALLED AN ATP PLT AND MY LCL TWR CTLRS. FRI WAS A HOLIDAY AND THE NUMBER FOR ZBW I HAD WAS NOT ANSWERING. ON 11/MON/88 I CALLED ZBW TO ASK TO TALK TO THE CTLR ON DUTY. THEY SAID THEY WOULD CALL ME BACK AND SEEMED VERY CONCERNED. I THEN FILED THIS FORM. I FELT THIS WAS THE FAULT OF NO ACTION TAKEN ON THE PART OF THE CTLR IN ZBW AND WONDERED WHY.