I did have the Hallett but it is now residing at Pier 57 in Chicago. My 38 has 525SC's. Toying with the idea of 540's or 572's and keeping the hull. Not sure which way to go. Put money into new power or take that money and the boat and put it into something that already has the speed and power I want.

Depends on your budget and what's important to you but given some of the things you said you were looking for, I'd upgrade to a newer 42 with 700/#6's for the following reasons:

- That boat will run north of 100 all day long
- Gives you the added length and comfort in the ocean when/if you want to go there
- Stock power so should be less challenging to finance
- If you're already thinking about a 42, it will continue to haunt you....
- Your 38 is already 14 years old; if you put a lot more money into it now; you probably will not recover that later if you sell it
- Easier to sell your 38 with stock power.

A 42/525 boat running north of 85 is rare; BeakBoater's friends 42 seems to have an exceptional setup to achieve that number but most 42/525 boats will run low 80's.

Yes I need to ride in a few 42's.

That's what I was getting at,,,,, a buddy has a 2006 42 525 EX I work on,,,, tried props,,,, drive spacers ,,,,, I have the top speed in that boat in the Lake Cumberland Poker run a few years ago at 86 MPH,,,, and it took a LOOONG time to get there

Heck. 82 in a boat that weighs more then 12k on stock NA power would be good enough for me.

I agree with HyFive578 you have the bug for a 42 you might as well go that route with the power and speed you want

600's will get you maybe 90 w blue printing and set up. 700's will get you 90 with stock lowers and no blueprinting.. if you get good set up and drives you can get closer to a hundred w 700's.. I would rather have a 42 with huge power and 6 drives.. but much more $$ to go 9o plus.. and my 38 set up is around 10,000 puunds w trailer give or take so for me, its better cause i trailer a lot and tow it with mt 38' motorhome

As Paul Harvey used to say...."here's the rest of the story"
A couple of things to look at if you are seriously in search of 100 mph boat......Check with your insurance carrier. It seems to some carriers that 100-110 mph will negatively impact your pocket. I used Stacey at WakeZone Insurance, they will insure it....but you will pay.
The 525's, 600's and 700's from Mercury all used CMI headers, you can do a search and read about the nightmares concerning their failures. At 140 hrs, I put 2 new sets of headers on...not cheap also.
The 6 drives boats are pretty much bullet proof as far as the drive goes, the NXT transmission's a few had problems with them...we never did sold the boat with 150 hrs. With the 6 drive set up, you are locked into either Herring, or Mercury propellers, the 38's ran a six blade the 42's ran a 5 blade.....you may find a used set for $6000-7000. New will cost you more. Not everyone will work on it should you ding it.
Just a few things that came to mind when owned ours. The boat was a rush....acceleration was unbelievable for a couple of 502's with whipples...basicly what the 700's are. Never regretted owning it, ran 110 mph loaded with fuel and 5 people, ran 114 light on its best day.
If you go with aftermarket power you can work around the CMI issues and 700 hp isn't that hard to make reliably, but then you can get into some reliability issues with the bravo style drives on that boat with big power. So its a trade off.

Good luck

Yep best I get is 83-84 and Fountain "birth certificate" for my boat said 87 which I have never seen.

Have you had any drive issues? If the setup is reliable that isn't bad. Pretty much the same speed I get out of a 32, with HP500EFI motors.