One of the reasons I bought a Catalina: I sent the following message yesterday, my questions answered today. Very cool. Message sent: I have 77 Cat 27 with single backstay. I need to enlarge transom O.B. opening 2"-3" vertically to accommodate new motor. 1) What are the structural considerations? 2) Any reenforcement needed? 3) Should I convert to split backstay? Please comment. catalina@catalina.net wrote: Joseph, Before doing that, be sure that the motor can't go down any farther by cutting the bottom side. You can also place a 2X8 on the back of the transom to move the motor out and that adds to the clearance. If you still need to cut the upper edge, either go to a split backstay (you can then make it adjustable, an added benefit) or place a backing plate across the inside of the motor well and bolt the existing chainplate through it. Thanks! David Graas, Customer Service.