56ci omc exhaust housing adapter

[Hall]

I'm putting together a motor for my critchfeild. I have 15 mid with a nitro gear case and a 56ci motor. I have changed out the exhaust adapter for the 56 power head. But the adapter difference between the 56 and 49 is that the 56 is a little thicker. So it makes the steering tube a little short so I can't put the lock ring back on and there is to much play with out the lock ring. I know some of you guys have made this work. I would like to know what you other guys have done. I know I can mill it down. But will I have to mill down where the motor mounts are.

Any help I will be great.

[sharpeye Mike]

Hey Hall, you have to machine the top of the adapter plate about 1/4" off the top, the spline on the drive will also be 1/4" deeper in the crankshaft where it belong.
Mike

[Fast Fred]

the mount height is the same on the 20" as the 15", the power head sits higher on the 20" adapter,

[Fast Fred]

the bolts in the upper mounts have more diameter on the 56, just send a drill bit through the 49 yoke.