Repowering a Cat 30
John,I repowered a couple years back. As I recall, there were two restrictive dimensions within the engine compartment that caused us to choose Universal's (Kubota) M25XP over a perkins or Yanmar. Here in the US, Westerbeke diesel has assumed distribution of the Universal diesel line, and offers several diesel models that will work, but none are true "drop-in" replacements.First, consider the space between the timbers just forward of the stuffing box where the new motor's oil sump must reside. This space is narrow, and would not accomodate the Perkins due to the width of the oil sump. I belive there is a narrow oil sump now available for the Perama line of Perkins diesels that would overcome this restriction.Second, the height and length dimensions within the engine compartment are restrictive. I found that the Yanmar was somewhat taller than the Universal. Although, I have heard of a Yanmar or two having been fitted in here in the US. Never-the-less, whichever route you choose, you will probably have to make some modifications to engine mounts, the top setee cover, and perhaps the forward engine access hatch.We found the alignment of the Universal (Kubota) mated with a Hurth transmission to be the easiest to fit. Some modification to your existing motor mounts may be required.You might look at Westerbeke's website, as a wealth of info and specifications are given there.Also, the engine compartment cover with blister (to accomodate added motor height) are available directly from Catalina.