I am looking at a Nortech 340 with the above engine options. I realize the 300s have a 5 year warranty with a 2 year warranty for the 350s. What other considerations should I be looking at? Will there be quite a difference in longevity? Thank you.

I had a 14' 34 nortech with triple 300's. Are you considering triple 350's or twin 350's? You realize the 350's take high octane. twin 350's will run about the same has 300's and will cost just about the same. Will get about the same in gas as will but high octane only. Considerable weight difference as well. Are you comparing Mercury to mercury?

My buddy has had a 34 Fountain and now a 38 Fountain with triple 350 verados. The motors have been good. The only knock is the 350 gets a lot of salt on the motor due the cowling intake on the front for the air and superchargers. His motors are on set backs too.
They sound bad a$$ at 6800 rpm redline and are about 6mph faster than the 275's he had before the 350's. Way more acceleration too.
However 5yr warranty is something to strongly consider.

the 350s need 91 octane or they will fail,merc can't figure out how to make the knock circuit work on the these motors if 91 is always available you would have less maitanence and less weight on transom but less warranty

Thank you for the replies. Boat would be run on LOTO. Looking at triple 300s vs triple 350s 'Mercury. I have access to 93 octane at all times. I think the 300s will propel boat to 75 while 350s should be 85. Additional upgrade from 300s to 350s is $7,000/each. I don't see too many 350s while 300s are very popular. Worried about what might happen after 2 years of warranty on the 350s.

RB-

Tried to PM you but your inbox is maxed out.
I'm headed to Fort Myers next weekend to sea trial a 340 as well as tour the NT factory w/ Mr. Sobo.

I was under the impression that the Merc 350 was a 1yr warranty.
I don't believe I've ever seen a Triple 350 pleasure CC 35' or smaller, mostly fishing boats 38'+ but thats just my personal experience.
Might be a tough resale, lots of HP, cost & no warranty (assuming you keep the boat more than 1yr)

Just my $.02

There might be some surprises at the Miami boat show this year regarding Verado's

Just cleaned up inbox. One ran at LOTO last year at 85. A 34 sunsation ran this year at 82. Both with trip 350s. But you are right. Quite a bit more $.

Not at ft lauderdale? What changes do you see coming?

Long rumor that Miami , Merc will upgrade the 300 to 325 or 350 with warranties but it's just a rumor.