MY 1979 j-30 HAS AT LEAST ONE BAD ENGINE MOUNT CAUSING THE RUBBER PIECE TO BOUNCE INSIDE THE CAST ALUMINUM MOUNT. DID J- BOATS SUPPLY THE MOUNT OR YANMAR? THE YANMAR DISTRIBUTOR SENT A MOUNT THAT WILL PROBABLY WORK BUT IT DOES NOT HAVE A CAST ALUMINUM BASE . INSTEAD IT HAS A 14 OR 16 GAUGE STEEL PLATE WITH THE BOLT HOLES FOR MOUNTING TO THE HULL BUNKS. MY QUESTION IS " IS THIS AN IMPROVEMENT IN THE ORIGINAL DESIGN OR DO I GO TO TILLOTSON TO GET THE RIGHT ONE?