Inliners International Forums General Discussion Engines Using a 153 torque plate on a 250

Since you have such easy access to it go ahead and do a comparison to see.
Also, the 153 was in production a full year or more before the 230 was. So, to say the 153 was patterned after the 230 may not be accurate since it came before the 230. It does however share the same bore and has other similarities to the 6 cylinder.