I got 65 MPH, MAX GPS that was calibrated and radar on my 1995 24' with 454/365 gil, bravo 23" labbed,cupped mirage plus, 750 Barry Grant, small, bigger cam and intake. Spedo alway read 73 but it was way off boat only did mid 60's. (( I would race guys that said they did mid 70's and we would do the same speed )) GPS need to be calibrated to elevation or they are not accurate guys, spedo's are always wrong and I don;t mean the spedos you wear.

If your boat is only going 65 with 365 HP, something is not right. This is the first I've ever heard of GPS calibration. My 8 yr. old handheld GPS reads the same speed as my new GPS speedo.

When i was running w/ seans boat in 2004, he was ahead of me and not really gaining much. I was running 65-66 wot and he said he was running 73 on speedo. He was probably doing more like 68-69.

But thats just splitting hairs.
His boat was nice and clean when i saw it and he seemed like the type of guy who'd take care of his stuff.

If i was interested in a boat, and it was gps'd a few mph slower than the owner said, it wouldn't stop me from buying, but 10mph is another story, especially if I wanted to be where the customer indicated.

As far as speeds go for the two boats:
My 1989 24' Pantera powered by a stock 330HP 7.4 carb engine ran a best of 65mph spinning a 23p 3 blade. Most of the time I ran a 4 blade and she would top out at 60-63mph depending on the load.
My 1997 24' Super ran 1-2mph faster with a stock 310HP 7.4MPI. Now with the 502MPI she runs 72-76 depending on the load.
I would say Storm is right on with the Merc speedo readings. If Sean was seeing 73 on his speedo it was in all likelyhood about 68 GPS.
My speedo reads 75mph for 70 on the GPS and 84 on the speedo is 76 GPS.
I too have an eight year old hand held GPS with no calibration required...

Pat, hows your boy likin the boat?

Henry loves the boat these days, especially when he drives sitting on my lap...
It's hard to keep him from pushing the throttle too far. He doesn't quite understand that his 8 month pregnant mother can't handle getting bounced around...

Hey Storm,
Did you finish your addition?
Is it time for another boat?
I'm thinking your youngest is ready and I know your son has to be missing the boat...

As long as we are all on the same page of not knocking Superboats !!!!

Addition may not be done till November... with any luck.
And that would be fast.
I'm pretty busy w/ the renovation and wouldn't of had anytime for the boat.
I think my son wants me to get a whaler to go tubing an skiing.
I just hope i can cover the bills for the house.
With the way it keeps going, I coulda gotten a 39OL.

Here's before and current from a week ago.
Fully gutted.

We are on Lake Norman in NC, Just north of Charlotte. We are looking for an I/O. Sorry outboard guys, I am not a fan of outboards. If anyone has a supperboat in the area, would like to look over and get a feel for them. Hard trying to find a good boat, and all that is around is bajas, etc. Fountain would be OK, but do not want to spend that much now. Have been on a pantera, and liked it. Superboats and sutphens seem to have similar hulls (7 ft beam, etc.). Just been hard to find a boat, aswill need to travel to look, etc. In the middle of a full house remodel and working on starting a business, so makes it hard. Sometimes think of just grabing a local baja; however, have not done this yet.

This supperboat is on Lake george now. Looks pretty clean. Thinking of whether to make an offer or not.

Thanks for all of the feedback.

Court my old boat is in your locale.
And didn't mean to derail your thread.