Keep in mind the 700 tranny's blow up now and then.

On a previous Nor Tech with trip Potter 850's I got 300 hrs before first rebuild and subsequent rebuilds were 225 to 250 hrs max. Not sure what you can expect if Mercury engines.

Friend of mine got about 225 hours out of his 850's before rebuild, they are in a 36 nor-tech......he does not baby them either.

Valves need adjustments every 25 hours or so? That could be a once a month trip to the mechanic in the summer months.....

That blue 39 was a Hideaway trade, Blume had it for sale for awhile and now PBB has it for sale for the 2nd time.

They are about a 200 hour engines as long as regular valve adjustments are done and they are serviced religiously.
You can easily turn them into 1075's with a camshaft, pulley and ecm change. It takes around $2000-$2500 worth of parts to do it. You may want to consider it around 75-100 hours and the valve springs can be done at the same time. Then you could go another 150 hours with regular maintenance.
I'm not to far from you and am capable of doing the work. Let me know if I can help. Good luck with it if you buy it.
Eddie

700 are great motors however the extra Torque you get with the 850's is well worth the extra cost... just my 2 cents...

I was curious to know how much more aggressive you usually go on the cam and smaller pulley swaps to get it up to 1075 or above standards?

I agree. The most power I've had so far is 575's, I want something that will RUN!!

To make it real simple you just use the actual 1075 cam and pulleys. You can also buy the actual 1075 ecm, or have the 850 ecm programmed to the 1075 specs.
Eddie

We love our 1075s. Really dock friendly and run like a raped ape when you want them too. Have 115 hrs on them. Great motors if you keep on top of the maintenance. 850s are just a smaller version, very easy to upgrade.