I am looking at a mid 80s 272 with the 260's Does anyone have one of theese that runs 75 to 80 with modified small blocks. OR Would I need to change everything to get the speed up like 502 mags and bravos?

You won't see 75-80 in that boat with small blocks unless you can get like NASCAR type hp out of 'em (750 )

That's a fairly big heavy hull. Even with 454 Mags back in the day, 70-72 was tops.

A local guy has one with the 350/260's and alpha drives (EEEW!). I seem to remember him saying 63/65 on the speedo. (GPS would be lower). A good friend had one with 454/330's that were bumped to around 375-400hp that pulled 73-75 on speedo. 3rd 272 just brought to the area has 2001 500efi's and ran 83 GPS but couldn't hardly get on plane (props too big). Props were changed which increased overall performance and boat hits 78 GPS now.

I wouldn't change that over to big blocks/ Bravo's - 272's w/ that package sits very azz heavy.

One trick is to swap the port Alpha drive (or change the gears yourself) for a counter rotating one as that boat most likely has both RH drives on it. With the right props that could add another 5+ mph. If you threw some small superchargers on there I'd bet that would get you mid 70's.

Has anyone switched one to a single? Looks like some major stringer work though.

Plus it's a heavy boat for a single unless you have some MAJOR power. I have t/540s and see mid to upper 80s

Mopower, I hope your putting some hours on those bad boys, hopefully a trouble free summer

Masi,
Pretty much trouble free this year. Still have a slightly rich problem which wasn't there on the dyno. I have an Innovate Air/fuel meter and at cruising speed I'm running 10.9/1 A/F and plugs dark brown. Better safe than sorry. Adjusted floats again and have to try again. My engine builder says it could also be the exhaust in the boat causing it to go richer too. Other than that it runs like a raped ape
Also have a set of 30" Bravos to try. Got 28s on there right now and turning 5600/5700 rpms

Is it very stern heavy with the 540's?

Nope.
Aluminum heads , intake , and exhaust manifolds. They are Merlin blocks and they are heavier but Merlin heads are near 80 lbs each , my Canfield alum. are 38 lbs each. Merc cast iron exhaust manifols and elbows will tun your face red trying to lift them. My Imco Power Flows can be handled with one hand. And the Team G intakes are probably near 1/2 the iron Merc intakes were .