Sorry Oldmics. That one went over my head. I didn't notice the smiley faces after your note. Yes, every Y-Block for sale is a 312. Lol
Y-Blockhead,
The '54 Fords Police Interceptor was a Mercury 256 Y-Block. The car you mentioned must have had the carb replaced somewhere along the line. It came with a unique Holley 2140 4 barrel that had a hand throttle lever on the pass. side of the carb. I guess so they could elevate the idle RPM for better battery charging. The carb was LIST # 885. Yes, the interceptor did get the station wagon Dana rear axle too. There used to be a '54 Police brochure on the Old Car Manual Project, but last time I looked it was gone.
The only WCFB's used were on some '56 Mercury's with vacuum secondaries and on '57 Lincolns. Lincoln Mercury seemed to like Carter carburetors more than Ford.
Sal