Sonic 260 prowler top speed
 

I just picked up a 1998 sonic 260 prowler. I really love this boat because of the cabin layout and many other nice features these boats have above all the other boats in its class.

I am looking to possibly put my 700 hp 555 CI engine in this boat. I was curious what kind of speed I may see with this set up? I also have an imco extension box and -2 shortie I may add to it as well if there would be any larger gains.

I like that boats layout to. I believe it was a 60-65 mph boat with a 502mpi (415 hp...but I believe that was prop shaft rated with a bravo). Sydwayz had a Prowler with a 500efi in it many moons ago. He will probably chime in with the speeds he got. Without any specific knowledge I would guess 75-80 with 700hp, an extension box and -2 shorty. Hopefully some people with more specific knowledge like Sydwayz will chime in.
John

Best ever on my 1999 500EFI was 72mph. You may scare 80mph on a perfect day.
The bigger question/issue is torque, where it is in the band, and the fact that boat weighs 5500 lbs. or so. You are going to need a FULLY beefed up Bravo derivative drive to hold up for a while and probably full tear down and inspection each off season.

I have a 98 prowler, had it since new, never had stock power in it. best I seen so far is 85.i do think I can get more so i'm putting a pair of holley 850's on it now, had a pair of 700's on it, it ran fine with them. currently I have a 540 420 mega blower in it. I have spoke to a couple of people that had shorty's on there boat and they didn't gain anything. I do think the extension will help with speed. you defiantly want to put a nose cone and external steering on it. at 85 for a heavy boat there is NOT much of the boat in the water and you have to really pay attention to the water. I cruise at 60 mph with a 30 pitch 4 blade bravo one. speaking of bravo one, my drive is the original one, did nothing to it but change the oil, I never hammer it out of the whole and I always use my tabs. where are you located ? Dave