POSI WAS NOT OFFERED ON 55 AND 56 FORDS AND T-BIRDS. I WANTED ONE. WE DETERMINED THAT THE REAR END IN THESE CARS WAS A 'DANA 44' HYBRED. (MOPAR LIKE CENTER SECTION WITH FORD 9 -INCH TYPE TUBES AND WHEEL BEARINGS. SO, IF A MOPAR CARRIER WITH POSI WAS CHOSEN- IT WOULD FIT THE CENTER SECTION. BUT>>> THE CARRIER BEARINGS FROM A MOPAR WILL NOT FIT IN THE FORD CENTER-THEY WOULD BE 'TOO BIG'. PEOPLE TOLD ME TO CALL REIDER RACING AND THEY KNOW ALL ABOUT THIS SWAP. THEY HAVE IN STOCK THE CARRIER, SPECIAL SMALLER O.D. BEARINGS AND POSI FOR SALE>>ALL AT ONE PLACE. ABOUT $450.00 WILL GET YOU WHAT YOU NEED/ YOU DON'T HAVE TO REPLACE THE RING AND PINION IF THEY ARE STILL GOOD AND YOU LIKE THE RATIO YOU NOW HAVE. JUST GET A SHIM KIT FOR A DANA 44 AND 'TIGHTEN IT UP' WITH THE PROPER SHIMS. (I DID). WORKS PERFECT!!! THE POSI UNIT IS NOT AN EATON TYPE- IT HAS

SPECIAL 'GEARS' AND RAMPS IN IT ---REIDER WILL TELL YOU HOW IT WORKS. I HAVE 4,000 MILES ON THIS UNIT AND HAVE NO COMPLAINTS AT ALL. (I HAVE 55 T-BIRD WITH Y-BLOCK 292/BLUE THUNDER/HOLLEY/3 SPEED CRUISE-O-MATIC) OH, IF ANYONE WANTS THE DATA ON THE 3 SP CRUISE-O IN A EARLY Y-BLOCK-I HAVE THAT KNOWLEDGE,TOO. CALL ED AT 419-377-9449 OR HOME> 419-476-4437 > IN TOLEDO OHIO. BYE .