I have seen a few with twin 500s listed for sale over the last couple years, one was at Pier 57 last year I believe. The owners usually claim low to mid 80's, which would make sense since a single 575 29 will run low 80's.

My boat has been converted to full hydraulic steering (to the helm) and trimmed 380 k plane plates added. This was done thinking that the chine walk would disappear. Both of these additions didn't help my boat at all. As soon as I get to 78-79, it starts walkin! Dropping the tabs down until it stops slows the boat down. I've got a pair of 540's in my boat and I can't use them to their full potential. As soon as I hit the low 80's @4600 rpm (32 pitch bravo 1's) it gets really unstable.

I've always wanted to upgrade the power on my 29 and get into the 90s. Anyone have experience on what a single 29 is like between 80-95? Thanks.