John, Just search this incredible site for XDP and read on.
Stay away from the XDP drive not even thinking about the heads. Just my humble 2 cents. BTW, i have the same single engine config in a 27 and no compression problems with about the same hrs.
Good Luck!
Who's the dealer?
Interesting, these XDP issues. I've noted that there are a lot of negative opinions expressed on this form about VP - is this mainly beacuse of the XDP problems?
An interesting factoid about the XDP drives is that they have never been available here in Sweden - which is Volvo Penta's home market and where 95% of all sterndrive boating is in salt (well, brackish) water. One would have thought composite drives would be ideal for this environment - but evidently the XDP drives are/were U.S market only. Odd.
VP, obviously, being a Swedish company, has a rock solid reputation over here - here it's more like "stay away from Bravo drives, they eat gimbal bearings".
Maybe that's the reason they never offered the XDPs in EU - afraid they would ruin the brand's reputation?