I'm replacing an MD 17C with a Yanmar
3JH5E. The MD 17C ahs the same mounting brackets that are shown in your drawing and photos, but it does not have the down angle transmission. My old beds are inclined at 15 degrees to match the prop shaft. I'm rebuilding the beds to get to an 8 degree incline, and I'm using a transimission with a 7 degree down angle.
Oddly, because the aft brackets on the Volvo are so much higher relative to the crankshaft than the front brackets, I will end up keeping the aft end of the beds at about the same level, while raising the front end slightly.
Sketching a side view of the old engine with the new engine superimposed on it, showing the line of the beds and the distances from the mounts to the shaft flange in rough scale, including all of the angles, is helpful in figuring out how to make it all fit. Also, as a previous post suggested, building a mock-up of the new engine is a great way to get an understanding fo what's happening. I made mine out of 2" by 1/8" aluminum
angle, which I will reuse for other little projects. Pictures are on the blog below.