looking at Silverton 410 need advice on the engines

I wouldn’t get a gasser over 38/40’ unless you plan to use it as a dock queen or mostly at hull speed. That said silverton are lightly built so performance should be ok.

how many hours do you plan on putting on it every year? Less than 50 to 60 gas is ok. Above that you ll be better off with diesel.

also, diesel is much safer and diesel gens are much more reliable as well

The 8.1 GM large block replaced the 8.2 a few years back and is the last of the GM large blocks.
It is able to make a lil more HP (consume more fuel) than the 8.2 but I never felt it was a better engine.
Merc and VP use the heck out of them for gas applications, mostly because it is the only large block available, IMO; NOT because it is a great block.

OTOH; Talk about a great block that also happens to be diesel, Yep, the Cummins 6.

If you have to have a Silverton and you have a diesel option, it is a no brainer, go with the diesels...
If your looking at anything over 40 foot and available with serviceable diesels, go here always over gas.

For ship & giggles, have you talked with your insurance agent about this subject?

More money up front but also will get more out of diesel on resale. You will also find a much larger buyer pool for diesel vs gas when comes time to sell. If you need more convincing just search Youtube for videos of gas boats exploding at the fuel dock when refueling.