Why don't you just use the dolly whole and attach uprights to hold the motor?
That is what I did, works like a charm. I've never started a motor on it though.
Well, I built the engine dolly first and then bought the furniture dolly later. I was pleased to see it was the perfect size. Once I sell the engine, I'll want to use the furniture dolly for other things. I find it to be less work to keep the furniture dolly as a separate piece.
