i wasnt for sure , being that i deal mainly in bbc , but being this is my first bbo do the motor mounts or frame mounts need to be changed from my sbo to be used with the 455?

 

The sbo mounts work fine with the bbo. You don't need to change anything. If you change to bbo mounts you would have to change the frame mounts too, but you can stay with sbo mounts they work for both sbo and bbo.

 

Unlike Chevy or Ford, the SBO and BBO are externally identical except for the deck height. The motor mount bolt holes are in exactly the same place on both. Prior to the 1969 model year, Olds used exactly the same mounts for the BBO and SBO. For the 1969-72 model years, the A-body BBO mounts were upgraded for strength and to incorporate an interlocking feature so that the mount would not separate in the event that the rubber came apart. This required a different frame mount to accommodate the larger motor mount, but the engine (as defined by the crank centerline) was in the same place. The SBO mounts were similarly redesigned for the 1970 model year and all replacement mounts now incorporate the interlocking feature anyway. Use the motor and frame mounts as a matched set (all SBO or all BBO) and any Olds motor bolts right in.