We repowered our 1989 with a 2000 200HPDI from a carbed engine, your carbed engine likely did better on fuel then our original, but we saw a significant increase in efficiency, also went from a 225 to a 200 and had no drop in speed and hole shot was better. 200 HPDI is a great engine, if you can get one left over and plan to keep the boat for years to come that is the way to go, if you might not hold onto the boat for more then 5 years, maybe a rebuild might suit you better, even with a good fuel savings you likely wouldn;t see enough savings unless you used the boat a ton in a short period of time. In the long run though the HPDI will save you money and last longer then a rebuild...assuming it is a leftover and new, or a lightly used one with proper maintanance records and hours of operation are at or near cruise, not at high speeds. I believe Gateway in Belford NJ has a leftover HPDI new, they did in the fall, not sure if they sold it or not, 14,500 was msrp when it first came out, I think they are closer to 10,000 now, depending on what price a dealer is willing to sell it at and cut from their profit. A rebuild will be expensive, but nowhere near the price of an HPDI, even a used HPDI in good condition will cost more then a rebuild, but the gap gets a bit closer.